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* Temporarily still under construction: the mixed prairie is immense in size and amazingly diverse in species composition with ambiguous boundaries. Please be patient.
Mixed prairie comprises the vast majority acreage of Great Plains grasslands. Mixed prairie was named for its most obvious floristic aspect: it is comprised of tall-, mid-, and shortgrass species. This mixed composition is not always present as there are posclimax tallgrass-dominated communities, even consociations of tallgrass species (eg. sand bluestem [Andropogon hallii]), on deeper and or sandy soils, preclimax shortgrass (eg. buffalograss [Buchloe dactyloides]) communities on shallow soils and generally more xeric range sites, and yet other grassland communities (usually consociations) made up almost exclusively of a single species (eg. western wheatgrass [Agropyron smithii] on swale range sites). Sometimes speakers will refer to mixed prairie as "midgrass prairie" to be consistent with tallgrass prairie and shortgrass plains and reflecting an overall physiogonomy that is intermediate (= "midway") between the latter two major forms of central-continent grasslands.
The ultimate reference for mixed prairie (and shortgrass prairie) from standpoint of descriptions of range vegetation and response to disturbance is--and will likely always be--the classic Grasslands of the Great Plains by Weaver and Albertson (1956). Definitive source of knowledge regarding mixed prairie from an ecosystem perspective is that of Coupland (in Coupland, 1992, ps. 151-182). The comprehensive monograph on shortgrass plains (=prairie, steppe) edited by Lauenroth and Burke (2008) overlapped--by necessity--parts of the mixed prairie so as to be a valuable reference for western extremities of mixed prairie.
General comment on organization: Arrangement of vegetational units in chapters and sub-chapters of Range Types of North America was based on classification and description of vegetation as established by such seminal works as Clements (1920), Weaver and Clements (1929, 1938), and Braun (1950) and not on (or according to) geographic region or physiographic province as was followed (sort of ) for forest cover types (Eyre, 1980) and rangeland cover types (Shiflet, 1994). In Range Types range vegetation was organized as to climax or potential units of natural plant communities at organizational levels extending from biomes or formations, associations, etc. down to range types and, in some cases, range sites. Certain of the major and more diverse associations (mostly Clementsian associations) or major subunits of biomes (such as mixed prairie in this instance) were subdivided into chapters organized by physiographic provinces or related natural geologic units (eg. Northern, Central, Southern Great Plains). Again, however, it was vegetation--not region or geologic province--that served as primary or fundamental basis of distinction and arrangement of chapters within this publication.
Southern Great Plains (Llano Estacado= Staked Plains) and Adjoining Tablelands Sandhills
143. Sand dune mixed prairie or, maybe, mixed prairie-shrub savanna- Vegetation is often deceiving. That fundamental principle was exemplified by this mixed prairie on dune land. Sparsity of vegetation cover and low density of plants would suggest to the greenhorn a desert, but in reality structure and composition of this range plant community consisted of tall-, mid-, and shortgrass species producing a classic mixed prairie (in spite of sparsity of plants and plant cover). Major grass species included little bluestem, sand bluestem, sand dropseed, sand paspalum (Paspalum stramineum= setaceum var. stramineum)and perennial threeawn (Aristida purpurea complex). There were a few plants of showy fingergrass (Chloris virgata) but presence of this annual species was of little diagnostic utility. Likewise the presence of a few specimens of common sandbur (Cenchrus incertus) suggested nothing beyond the ever-present annoyance of this weed. Under virgin conditions it was likely that big sandreed (Calamovilfa gigantea) and giant dropseed (Sporobolus giganteus) were present as key indicator species. Neither of these climax species was not found at this location.
The deception (and complication) of this dune land vegetation extended to the shrubs that were present. Mixed and shortgrass prairie grasslands and sand shinnery oak (Quercus havardii) shrubland develop in a mosaic of climax vegetation throughout this region. Presence of numerous shrubs that are climax in the "shinnery sands", the sand shinnery range type (ecosystem), were also present. These shrubs-- in certain proportions-- are thus climax components of the vegetation shown in above photographs. This range plant community was actually a transition zone (= ecotone) between grassland and shrubland vegetation such that it developed into a grass-shrub savanna. These shrubs included sand shinnery oak, the scrub growth (= coppice) form of honey mesquite, and (infrequently) sand sagebrush.
An estimate of annual biomass productivity (so as NOT to be confused by accumulated plant tissue that included necromas accumulated in woody species), species diversity, and plant cover of each growing season convinced this photographer-student that this range vegetation was clearly grassland and not shrubland. This conclusion was further bolstered by the almost-always assumption that that there had been some range deterioration (= degree of departure from climax) if, by nothing else the ubiauituous increase in mesquite since arrival of whiteman. Nonetheless, it was also obvious (again, at least to the rangeman taking these photographs) that this range vegetation was a mixed prairie-shrub savanna. The shrubs are a part of this climax.
Forbs included yellow whollywhite or yellow old plainsman (shown above in this chapter) and western sensitive-briar (Schrankia occidentalis) which was introduced in the succeeding photograph.
Local topography or land form on which this range cover type developed was hummocky (circular sandy hummocks) rather than the tall dune form. The first photographs was taken from the bottom of an interdunal basin in foreground with slopes and the rim or crest (top) of the hummock in background. The second photograph was taken from the intra-dune (intra-hummock) mid-slope (foreground) across the basin (which is bottom of this inter-dunal area) to the crest (behind which is another interdunal hummock with its basin, sloping sides, and crest or rim).
Monahans Sandhills State Park, Ward County, Texas. June. FRES No. 31 Shinnery Shrubland Ecosystem & No. 38 (Plains Grassland Ecosystem) transition zone. No truly descriptive Kuchler unit. SRM 708 (Bluestem-Dropseed), and a textbook of the sparse form or expression of this rangeland cover type. There was no appropriate series under the Brown et al. (1998) Plains Grassland biotic community: inadequate Series units for this large and diverse zonal or regional community of plains grassland climax. High Plains- Shinnery Sands Ecoregion 25j (Griffith et al., 2004).
144. Western sensitive-briar (Schrankia occidentalis) on dune land mixed prairie-savanna- A thick-stemmed, horizonally rank-growing native legume was doing just fine on the bottom of the basin of a circular hummock that formed in an inter-hummock space. Monahans Sandhills State Park, Ward County, Texas. June.
145. With wet blessings- Three scenes of climax grassland (or, arguably, a grass-shrub savanna in some local areas) of the Monahans Sandhills in an extremely wet warm-growing season. The first view was of of a slight rise on the rim of a vegetated sand dune above a local basin or depression in the dune. Plant species on this dune rim included sand shinnery oak (Quercus havardii), giant dropseed (Sporobolus giganteus), prairie sunflower (Helianthus petiolaris), common grassbur (Cenchrus incertus), annual wild-buckwheat (Polygonum annuum), soapweed yucca (Yucca glauca), and sand sagebrush (Artemisia filifolia).
The second of these three views was in the depression or "hollow" of a vegetated dune or sandhill. In this dune "hollow", prairie sunflower was the dominant plant species, but sand shinnery oak, giant dropseed, and plains yucca (Yucca campestris) were also present. The third slide presented climax range vegetation in an imaginary "photo-transect" upward on the slope of a sandhill above a depression or "hollow". In addition to sand shinnery oak, giant dropseed, and prairie sunflower a young plant of honey mesquite (Prosopis glandulosa) was present. These three photographs presented a summary or composite of the edaphic (soil-determined) climax vegetation of this range site.
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect. Peak standing crop of this range plant community. FRES No. 31 Shinnery Shrubland Ecosystem & No. 38 (Plains Grassland Ecosystem) transition zone. No truly descriptive Kuchler unit. SRM 708 (Bluestem-Dropseed), and a textbook of the sparse form or expression of this rangeland cover type. There was no appropriate series under the Brown et al. (1998) Plains Grassland biotic community: inadequate Series units for this large and diverse zonal or regional community of plains grassland climax. High Plains- Shinnery Sands Ecoregion 25j (Griffith et al., 2004).
146. Giants and other sorts in the sandhills- Top of a vegetated sand dune (or, more precisely speaking, a sandhill) in the semiarid to arid zone of the northeastern Trans Pecos Basin and Range Region. This range vegetation could also be viewed as an outlier or "island" of the Llana Estacado (Staked Plains) at their southern extremity. As such, this grassland was interpreted by this author as being more of a grassland of the Southern High Plains than of semidesert grassland typical of the Basin and Range physiographic province. This view was supported by presence of sand shinnery throughout the Monahans Sandhills being treated herein.
This local range plant community was dominated by giant dropseed--the predominant, perennial, herbaceous species of this edaphic (soil-based) climax vegetation--which was accompanied by the shrub form of honey mesquite (background of first slide), green carpetweed (Mollugo verticillata), annual wild-buckwheat, sand paspalum (Paspalum stramineum= P. setaceum var. stramineum), and sand stickleaf (Mentzelia strictissima).
Such vigorous, thriving plants can express this amazing growth only in those rare events of extremely wet summers. The author was blessed to be able to bring such remarkable examples of southern sandhills plant life to his www.edu viewers.
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect. Peak standing crop of this range plant community. FRES No. 31 Shinnery Shrubland Ecosystem & No. 38 (Plains Grassland Ecosystem) transition zone. No truly descriptive Kuchler unit. SRM 708 (Bluestem-Dropseed), and a textbook of the sparse form or expression of this rangeland cover type. There was no appropriate series under the Brown et al. (1998) Plains Grassland biotic community: inadequate Series units for this large and diverse zonal or regional community of plains grassland climax. High Plains- Shinnery Sands Ecoregion 25j (Griffith et al., 2004).
147. Local botanical "lake"- Population of prairie sunflower in the low-lying basin of a low sand dune in the northeastern perimeter of the Texas Trans-Pecos Basin and Range and southern extension of the Staked Plains. This plant community was what Frederic Clements regarded as a consocies, the seral equivalent of an association dominated--often overwhelmingly--by a single species. Sand shinnery oak was in the background.
Such "lush" stands of unusually large plants of this annual composite typically occur only in very infrequent, wet summers.
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect. Peak standing crop of this range plant community. FRES No. 31 Shinnery Shrubland Ecosystem & No. 38 (Plains Grassland Ecosystem) transition zone. No truly descriptive Kuchler unit. SRM 708 (Bluestem-Dropseed), and a textbook of the sparse form or expression of this rangeland cover type. There was no appropriate series under the Brown et al. (1998) Plains Grassland biotic community: inadequate Series units for this large and diverse zonal or regional community of plains grassland climax. High Plains- Shinnery Sands Ecoregion 25j (Griffith et al., 2004).
148. Giant and dwarf dominants on the dunes- Giant dropseed, a large cespitose grass, with the rhizomatous oak shrub, sand shinnery oak on deep sand in the Monahans Sandhills. These two species were the herbaceous and woody dominants, respectively, on this grass-shrub savanna.
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect.
149. Business end of a deep sand denizen- Sexual shoots with large panicles at anthesis on Monahans Sandhills during an extremely wet summer/early autumn.
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect.
150. Deep sand details- Panicle of giant dropseed, first slide, secondary branches with spikelets at anthesis, second slide, and close-up of many spikelets on a still-closely closed panicle along with part of a culm to its right, third slide, of giant dropseed growing on Monahans Sandhills.
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect.
151. Shoots on the sand- Shoot with culm and leaves of giant dropseed growing on deep sand of the Monahans Sandhills. Giant dropseed was the herbaceous dominant of a grass-forb-shrub (sand shinnery oak) savanna at an ecotone of the Southern High Plains (Staked Plains)-Trans-Pecos Basin and Range in southwest Texas. The white coloration in the background were flower clusters of annual wild-buckwheat.
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect.
152. Dry habitat for a panicgrass- Highly rhizomatous Havard's panicgrass (Panicum havardii) thriving on an otherwise bare sand dune in the Monahans Sandhills. Havard's panicgrass is closely related--at least, morphologically--to switchgrass (P. virgatum), but they obviously have vastly different niches especially with regard to habitat. Though perhaps"chauvistic" from perspective of Havard's panicgrass (to compare it to something more widespread, better known or more "powerful"), P. havardii could be described or thought of as "sand dune switchgrass".
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect.
153. Sprawling on the sand- Tillers (both vertical and decumbent shoots) of Havard's panicgrass on otherwise bare sand dunes in the Monahans Sandhills.
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect.
154. Sandy spikelets- Spikelets of Havard's panicgrass growing on a microsite of the deep sandy soil that formed a "bare" dune, a sand dune that was in this local area devoid of plant life other than that of Havard's panicgrass. These spikelets were conspicuously at peak anthesis with both stamens and stigmas exerted.
Monahans Sandhills State Park, Ward County, Texas. Early October; early autumnal aspect.
155. Sandy pardoners- Inflorescences of common grassbur or common sandbur (Cenchrus incertus) and sand paspalum (Paspalum stramineum= P. setaceum var. stramineum) growing on a sand dune in the Monahans Sandhills. Giant dropseed and honey mesquite were dominant plant species in the climax range vegetation of which these two grasses were associate species.
Monahans Sandhills State Park, Ward County, Texas. Early October.
156. An indicator of deep sand- Inflorescences (first slide) and details of inflorescence branch loaded with spikelets (second slide) of sand paspalum (Paspalum stramineum= P. setaceum var. stramineum) in heart of the Monahans Sandhills which is most aptly viewed as an outlier or "island" of the Llana Estacado (Staked Plains) at their southern extremity where they join the Trans-Pecos Basin and Range physiographic province. Sand paspalum is almost always found as widely scattered populations (long distances among individual plants). In spite of being sparsely populated, however, sand paspalum is one of the best indicator species of deep and duned sand throughout this region.
It would be neigh on to impossible to get a species range on sand paspalum because it is now generally regarded as a taxonomic variety of thin (thinseed) paspalum (P. setaceum var. stramineum) so that this former species and now variety is thrown in together with P. setaceum which grows about everywhere in Texas. Powell (1988, ps. 290-291) was very specific as to the limits of P. setaceum var. stramineum (= P. stramineum) as limited to the northeastern portion of Trans-Pecos Texas (found only Ward, Winkler, and Crane counties of this eastern portion of the Basin and Range physiographic province).
Coulter (1891-1894) listed P. setaceum but this certainly did not include P. setaceum var. stramineum; nor did he not list or describe anything resembling P. setaceum var. stramineum by any other name. Wooton and Standley (1915, p. 55) gave what was most likely sand paspalum as P. bushii which they distinguished from P. ciliatifolium (= P. setaceum ciliatifolium). By contrast, Silveus (1933, p. 523) did present a detailed description of P. stramineum (he gave P. bushii as a synonym) plus he gave a a full-page photograph of it and line drawings of its spikelets (Silveus, 1933, p. 541). Silveus, a lawyer by trade, was a sheer genius when it came to grasses! His manual on Texas grasses will likely never be surpassed. Hitchcock and Chase (1951, p. 608) also gave P. stramineum as distinct from P. setaceum (p. 607) and showed P. bushii as a synonym for P. stramineum. Gould (1951, p. 294) gave P. stramineum for sand paspalum, but later revised his interpretation and included P. stramineum as one of four taxonomic varieties of P. setaceum (ie. as P. setaceum var. stramineum), a view followed by Powell (1988, ps. 290-291) and Shaw (2012, p. 765).
Sand paspalum is nowhere near abundant enough to be a major forage grass, but it is a textbook example of an indicator plant, in this case, an indictor species of deep sand.
Monahans Sandhills State Park, Ward County, Texas. Early October; early grain-ripe phenological stage.
157. When the sand is wet- Large plants of prairie sunflower (Helianthus petiolaris) produced in an extremely wet summer/early autumn on Monahans Sandhills. Prairie sunflower grew as a local population that comprised a consocies, a seral equivalent of a local association. Like the more widely distributed Helianthus annuus, H. petiolaris is an annual.
Monahans Sandhills State Park, Ward County, Texas. Early October.
158. Capitulating in the sand- Three capitula (plural for heads) of prairie sunflower growing on the inner depression or "hollow" of a vegetated sand dune. These dunes are generally not bare dunes of "shifting sands", but are well-vegetated with foliar cover of the scrub oak, sand shinnery oak; grass species, especially giant dropseed; and forbs, the dominant forb being the annual composite, prairie sunflower.
Given that these dunes were remarkably well-covered by vegetation (see again above slides) they have been regarded and named as "sandhills".
Monahans Sandhills State Park, Ward County, Texas. Early October.
159. Beauty on the sand- Shoot of one plant (first slide) and details of its flower cluster (second slide) of sand or rayed palafox (Palafoxia sphacelata) growing on a dune in Monahans Sandhills in the far-south section of the Southern High Plains, the Llano Estacado (Staked Plains). This species will sometimes be found growing in colony-like populations, but more commonly sand palafox grows as widely specied individual plants as seen here.
Palatability of this species to range animals was unknown. Sand palafox is a member of the immense Heliantheae tribe of the Compositae, some tribal members of which are extremely palatable while others are toxic and generally avoided by grazing animals. Other than in small, restricted areas sand palafox is nowhere abundant enough to be a valuable forage species. It is attractive to pollinating insects, but mostly sand palafox delights the eye of appreciative rangemen.
Monahans Sandhills State Park, Ward County, Texas. Early October.
160. One of the most beautiful and delicate- Two capitula (heads) of sand or rayed palafox growing on a dune in the Monahans Sandhills in the Llano Estacado (Staked Plains) of west Texas. This composite forb is attention-getting, but it is not abundant (other than locally) enought to be either a noxious pest (weed) or a valuable feed plant.
Sand palafox has a relatively limited species range compared to many composites, but it has a limited occurrence in other sand dune habitats such as those of the sandhills in southwestern Nebraska and northeastern Colordo.
Monahans Sandhills State Park, Ward County, Texas. Early October.
161. Sticky in the sand- Sticky blazingstar or sand stickleaf (Mentzelia strictissima) growing in duned sand Monahans Sandhills in the Llano Estacado (Staked Plains) of west Texas. Sand stickleaf is one of about 12 Mentzelia species found in the Staked Plains and Trans-Pecos Basin and Range areas (Gould, 1962, p.). The shoot appearing to right of this sand stickleaf plant (first or vetical slide) was a pre-bloom female specimen of sandhills pigweed (Amaranthus arenicola). Observant observers will note that an immature female inflorescence "snuck in" both slides including in the the second or horizontal slide (upper right, slightly below, flower of sand stickleaf).
The name stickleaf, in general, comes from the condition in which the coarse-textured leaves--especially dead, dry leaves--adheres to objects that brush up against them. This feature, in particular, applies to the tendency of leaves and stems of Mentzelia species to become intertwined in sheep wool or goat mohair such that these plant parts are encountered during shearing and, subsequently, in tying and sacking fleeces. This is an annoyance and, may in some cases, result in dockage of (reduction in price paid for) grease wool or mohair.
Mentzelia species are in the family, Loasaceae. Good botanical (morphological) description of M. strictissima was provided by Correll and Johnston (1979, p. 1087). Allred and Ivey (2012, ps. 384-388) provided a key for the 25 Mentzelia species found in New Mexico including line drawings of some species including M. strictissima (p. 388).
Monahans Sandhills State Park, Ward County, Texas. Early October.
Annual in the sand- An individual plant of annual wild-buckwheat (Eriogonum annuum) growing in an interdunal (among/between sand dunes) space in the Monahans Sandhills in the Staked Plains (or, Spanish, Llano Estacado) of west Texas. In this view, sand shinnery oak provided a scrub backdrop while green carpetweed was the principal accompanying plant species. Other common plants included the native grasses, common grassbur and sand paspalum.
The annual life cycle (pattern of resource allocation for sexual reproduction) is one survival adaptation (one manifestation of natural selection or fitness) for harsh environments. This is the Raunkiaer life or growth form known as therophyte, an annual or ephemeral plant that completes its life cycle (goes from propagule or germule to propagule or germule; gametophyte to sporophyte back to gametophyte) quickly and when growing conditions are favorable (Allaby, 1998). Therophytes are most common in xeric environments such as deserts, sand dunes, alpine habitats.
Monahans Sandhills State Park, Ward County, Texas. Early October; peak standing crop, full-bloom phenological stage.
Completing life's annual cycle- Complete flower cluster, the inflorescence, (first slide) and closer-in view of individual flowers (second slide) of annual wild-buckwheat growing in an interdunal space in in the Monahans Sandhills in the Staked Plains of west Texas. This inflorescence and its flowers were on the same plant that was shown in the preceding slide.
Annual wild-buckwheat has a wide adaptation with periodic "flushes" high populations farther to the east in the subhumid zone of central Texas as well as in the arid or desert zone. For example, this author witnessed a population boom of annual wild-buckwheat in the West Cross Timbers on land where he had not noticed the species in 20 years. Perhaps a few plants had existed during this time, but they were sparse enough as to go unnoticed by experienced eyes. This "boom and bust" population pattern is typical of annual species. Annual wild-buckwheat is an occasional biennal and at least some of the plants in the population boom witnessed by this photographer had overwintered and then flowered as biennials. That phenomenon was included in Range Types of North America under the Cross Timbers portion of the chapter, Tallgrass Savanna.
Diggs et al. (1999, p.899) remarked that annual wild-buckwheat was distributed "throughout most of Texas" with it being more common on disturbed areas and grasslands.
Monahans Sandhills State Park, Ward County, Texas. Early October; plants at peak standing crop, full-bloom phenological stage.
162. Shinny shrub parts- Crown, shoots, and leaves in first, second, and third slides, respectively, of sand shinnery oak growing on the Monahans Sandhills.
Monahans Sandhills State Park, Ward County, Texas. Early October.
Great Plains-Great Basin-Colorado Plateau (Southwestern) Transition Mixed Prairie
163. Great Plains-Great Basin transition mixed prairie grassland- Landscape-scale photograph of what Brown (1998, p.119) described in a photo caption as a "Plains grassland-Great Basin grassland transition", "... a mixture of both Plains species (Boutelous gracilis) and Great Basin species (Hilaria jamesii, Oryzopsis hymenoides)" and "... shrubs are mostly fourwing saltbush (Atriplex canescens)". The range vegetation shown in this slide was an example of plains and mesa grassland described by Dick-Peddie (1993, p. 119) and quoted in the last paragraph of the preceding slide caption. This climax vegetation was a consociation of New Mexico feathergrass (= New Mexico needlegrass) with blue grama, galleta, and Indian ricegrass approximately "equally divided" and functioning as associate species. Sand dropseed was present at more than "trace amounts", but it was not a major component. Black greasewood (Sarcaobatus vermiculatus) and Bigelow sagebrush (Artemesia bigelovii) were the two most common shrubs with greasewood better represented. Fourwing saltbush was present (rarely) and perhaps as a relict species. None of these woody species accounted for more than trace proportions. Broom snakeweed was present but even more rare. Forbs were represented (barely) by Russian thistle and Thurber pepper-weed (Lepidium thurberi).
Relative utilization or degree of use of grass was light even under current conditions of exceptional drought. It was noted that sexual reproduction of feathergrass was remarkable for such short-moisture conditions. Winter precipitation had "saved the day" for this species.
Grand Canyon section of the Colorado Plateau physiographic province.
Coconino County, Arizona. Estival aspect during worst drought (exceptional rating) in Arizona history, June. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Gallata Steppe).SRM 716 (Grama-Feathergrass).
164. Vegetation of Great Plains-Great Basin transition mixed prairie- This photograph detailed at community scale the climax vegetation of the New Mexico feathergrass consociation of plains and mesa grassland, a variant of the regional gramagrass-gallata (Bouteloua-Hilaria) climax steppe. Dominance by a cespitose midgrass (a species of intermediate height between tallgrass and shortgrass) produced a physiognomy typical of mixed prairie, but absence of a tallgrass species resulted in absence of one herbaceous layer that was present in some of the other range cover types of mixed prairie.
Cover and dentisty of woody species were so limited that a shrub layer was also absent. This climax community was not a savanna-like shrub steppe, but rare presence of fourwing saltbush was of uncertain interpretation. Brown (1994, p.104) specified presence of fourwing saltbush in a similar transition grassland community located close to the one shown here, but neither Dick-Peddie (1993, p. 104-106) nor the the SRM description of this rangeland cover type, SRM 716 (Grama-Feathergrass), (Shiflet, 1994, ps. 94-95) specifically reported fourwing saltbush for this vegetation. The SRM description (Shiflet, 1994) was limited to eastern New Mexico which was essentially in the High Plains province rather than the Colorado Plateau as shown here. Likewise, none of these descriptions mentioned greasewood which was certainly the most common (least uncommon) shrub and one known to occur here.
Perhaps browsing by livestock and/or wildlife had reduced fourwing saltbush. It was conceivable also that grazing had shifted dominance from the regionally dominant blue grama to the co-dominat New Mexico feathergrass. Existing "on-the-ground" evidence argued against both of these outcomes. Species composition of vegetation in the wide right-of-way of Interstate 40 was not apparently different from that inside the range allotment except that the rarely encountered fourwing saltbush plants were larger in the right-of-way. Right-of-way vegetation had been protected from grazing and routine mowing for several decades and this could explain larger size of fourwing saltbush specimens. Otherwise the only difference between livestock presence and absence appeared to be in degree of use (and not species composition of plant community). Present (and immediately past) grazing management of the range appeared to be ideal, an example of outstanding stewardship.
Fourwing saltbush was present (far right to center midground) on New Mexico feathergrass-dominated range protected from livestock grazing and not subjected to highway mowing (shredding).
Coconino County, Arizona. Early estival aspect (conditions of exceptional drought), June. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 716 (Grama-Feathergrass).
165. Patch dynamics in vegetation of Great Plains-Great Basin transition mixed prairie range- These paired photographs showed details of undisturbed vegetation (first or upper slide) and disturbed vegetation (second or lower slide) of a New Mexico feathergrass-dominated (feathergrass consociation) bunchgrass steppe on the Grand Canyon section of the Colorado Plateau province. The localized "patch" in the lower photograph had Russian thistle (round-shape tumbleweed in lower left), greasewood (largest plant; center background), Bigelow sagebrush (to immediate right of greasewood), fourwing saltbush (immediately to right and also behind Bigelow sagebrush), broom snakeweed (right background), and Indian ricegrass (right-center foreground) as well as New Mexico feathergrass in contrast to the nearly single-species stand of New Mexico feathergrasss in the undistrubed patch shown in the upper photograph. This was an example of patch dynamics on a very local scale (microsite-size). Both patches were on highway right-of way not subjected to mowing.
Coconino County, Arizona. Early estival aspect (in exceptional drought), June. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 716 (Grama-Feathergrass).
166. New Mexico feathergrass (Stipa neomexicana)- Two specimens of New Mexico needlegrass or feathergrass that were in the vegetation of a Great Plains-Great Basin transition mixed prairie range. Plants were at seed-ripe to seed-shatter stage. Cococino County, Arizona. Severe to exceptional drought conditions, but adequate soil moisture from winter precipitation enabled these cool-season natives to complete their purpose in life: pass on their deoxyribonucleic acid to the next generation.
167. Spikelets of New Mexico feathergrass- Three mature florets of New Mexico needlegrass remain in the otherwise spent panicle. Yavapai County, Arizona. June.
168. Grains of New Mexico feathergrass- Three caryopses (each still enclosed within a palea and lemma, the latter of which had a sharp-tipped callus and a characteristic twisted awn) of S. noemexicana. These showed the potential for mechanical injury to grazing animals. Coconino National Forest, Coconino County, Arizona. June.
169. Bigelow sagebrush (Artemesia bigelovii)- Both this species and big sagebrush (A. tridentata) grow in the Great Plains-Great Basin transition mixed prairie steppe on the Colorado Plateau. Bigelow sagebrush can be readily distinguished by presence of numerous stems in contrast to the usual single trunk of big sagebrush.
This specimen was growing on the climax New Mexico feathergrass-dominated range and exclosed area shown above. Coconino County, Arizona. June.
170. Another range of Great Plains-Great Basin transition mixed prairie- Another blue grama-galleta range in the Great Plains-Great Basin vegetational transition zone with a slightly different botanical composition than the one described immediately above. New Mexico neetlegrass or New Mexico feathergrass was still the associate species, but on this range alkali sacaton was the fourth-most important grass instead of Indian ricegrass which was roughly equal to blue grama and galleta on the previously portrayed range. Another major difference was in the shrub component. Whereas black greasewood was a major shrub on the previously described range vegetation, Nevada joint fir or Nevada Mormon tea (Ephedra nevadaensis) was the dominant shrub in the range plant community featured in this slide-caption set. Greasewood was absent from this range plant community although Bigelow sagebrush was preent in both range plant communities.
A local colony of Nevada joint fir or Nevada Mormon tea was present in midground of both slides, a larger and a smaller colony in the first and second "photoscape", respectively.
This range had been in Extreme Drought (Palmer Scale), but had received abundant rainfall from recent (two weeks previously) showers so that plants were in early "green-up" This range had not been grazed by permitted cattle during the previous growing season (year) which, combined with limited decomposition due to drought, resulted in presence of most of last year's herbage along with young shoots of the current growing season. Made for nice photographs of a truly beautiful arid grassland range.Truly amazing--if not miraculous miracelous--what Mother Nature can do if given a chance, and this was in a horrid drought!
Coconino County, Arizona. Mid-July; early shoot-gowth stage of phenology so more like vernal than estival aspect.
171. A joint operation- Local colony of Nevada joint fir or Nevada Mormon tea (Ephedra nevadaensis) on a blue grama-galleta dominated semidesert grassland in the southern Colorado Plateau. The first of these two slides presented a portion of that colony while the second slide offered a view into the interior of this group of shoots. E. nevadensis commonly grows "...in large pure stands..." comprised of plants with "... an expanded root crown..." (Francis, 2004, p. 307). Hence the expansive colonies frequently seen in southwestern deserts and semidesert grasslands. Almost all descriptions of Ephedra made reference to the "much-branched" habit or morphology of this group or of individual species.
Ephedra is the sole genus of Ephedraceae, the Mormon tea or jointfir family, and, for that matter, the order of Ephedrales. Some of the older botanical treatments such as Colter (1891-1894; ps. 552-553), Tidestrom (1925, p. 56) and Dayton (1931, p. 12) included Ephedra in the expanded family, Gnetaceae. Nevada jointfir is one of the shorter-shooted Ephedra species. All Ephedra species are dioecious. As there were no cones on the specimen shown here its sex was unknown to the author.
Bureau of Land Management, Coconino County, Arizona. Mid-July.
172. Joined joints- Two views of shoots of Nevada jointfir or Nevada Mormon tea on blue grama-black grama-galleta semidesert grassland on the southern Colorado Plateau. Basis of the common name of jointfir (sometimes joint-pine) was obvious in these two slides.
One good reference, complete with line drawings, for Ephedra species of the southwestern deserts was McMinn (1939, ps. 44-48) although this work did not offer a good description of vegetative features of the species nor did descriptions in Shreve and Wiggins (1964, ps. 224-226). Dayton (1931, ps. 12-13) and Vines (1960, p. 38) also gave apt descriptions along with line drawings. One of the best recent treatments was Francis (2004, ps. 307-309) who concluded that Nevada Mormon tea furnished browse and cover for wildlife, at least during winter and drought. As was typical of the older literature, Dayton (1931, p. 12) specified that Nevada jointrir provided browse for domestic ruminants on winter range with its palatability to cattle in winter approaching 40% (whatever that meant in the range vernacular of a more practical time).
First slide: Bureau of Land Management, Coconino County, Arizona. Mid-July. Second slide: Petrified Forest National Park, Navajo County, Arizona.
Great Plains grassland in Colorado Plateau- A blue grama-dominated (Indian ricegrass, galleta, and needle-and-thread were associate species) grassland-shrub savana used as a cattle range in southeast Utah. Shrub species included fourwing saltbush (Atriplex canescens), Wyoming big sagebrush, green Mormon tea (Ephedra viridis), and winterfat (Eurotia lanata). Forbs were scarce, sparse, whatever with the principal one being the native wooly plaitain (Plantago patagonica).
This cattle range in the arid Colorado Plateau had been heaviy grazed early in the growing-grazing season and then destocked of cattle so that there had been proportionately greater degree of use on the cool-season needle-and-thread and Indian ricegrass than warm-season eragrostoid grasses resulting in shifting the species composition of this savanna range to greater cover of the warm-season species, especially the dominant blue grama.
Presented at end of this short section were fenceline contrasts in utilization on this cattle range compared to degree of use on immediately adjoining range vegetation on a highway right-of-way open only to wildlife.
Bureau of Land Mnagement allotment, Monticello Field Office, San Juan County, Utah. Late July, estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 502 (Grama-Galleta). Cold Temperate Grassland142, Great Basin Shrub-Grassland 142.2, Mixed Bunchgrass-Shrub Series 142.22 (Brown et al., 1998, p. 40). Colorado Plateaus- Semiarid Benchlands and Canyonlands Ecoregion 20c (Woods et al., 2001).
Transition grassland in Colorado Plateau- Range plant community of a mixed grass-shrub savanna form of mid-grass prairie in the Colorado Plateau that developed on a highway right-of-way that was open to grazing by wildlife and not livestock. This rangeland vegetation was part of a broad ecotone or transition grassland between the Great Plains and Great Basin Desert. Grasses included the dominant Indian ricegrass with blue grama, needle-and-thread, and galleta (in that relative order based on foliar cover) as associates. Shrub species included fourwing saltbush, Wyoming big sagebrush, green Mormon tea, and winterfat. The only forbof any ecological significance was wooly plantain.
These two slides provided a pair of nested "photoplots" with the first slide giving a sweeping landscape-scale view while the second slide served as the "nested" photographic sub-plot of the first.
There had been almost zero utilization (no real detectable or meaningful degree of use) of any range plants on what amounted to a de facto livestock exclosure. Plants of the cool-season needle-and-thread and Indian ricegrass were dormant while shoots of blue grama were still in early to mid-growth and those of galleta had barely begaun to initiate growth.
Bureau of Land Mnagement allotment, Monticello Field Office, San Juan County, Utah. Late July, estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 502 (Grama-Galleta). Cold Temperate Grassland142, Great Basin Shrub-Grassland 142.2, Mixed Bunchgrass-Shrub Series 142.22 (Brown et al., 1998, p. 40). Colorado Plateaus- Semiarid Benchlands and Canyonlands Ecoregion 20c (Woods et al., 2001).
Note on grassland classification: the savanna form of this Colorado Plateau arid to semi-arid grassland could be interpreted as a form of semideserrt grassland, but given presence of mid-grass species such as needle-and-thread accompanied by the shortgrass species, blue grama, a dominant of the Great Plains (both shortgrass plains and mixed prairie), it was felt that this grassland range type was most accurately described as a transition zone or ecotonal grassland, the ecological and plant taxonomic affinity of which was more closely aligned with mixed prairie . Hence, its inclusion in this chapter rather than those devoted to semidesert grassland. Admitted, arbitrary.
Note on "conspicuous by its absence": Cheatgrass (Bromus tectorum) was not in evidence on either the grazed or "fenced-out" range. Undoubtedly there was cheatgrass on this range, but plants of this invasive Eurasian annual were so "few and far between" that this photographer rangeman did not see enough to justify calling it present even at trace amounts.
Principal plateau players- Dead (and ungrazed) shoots of now-dormant plants of Indian ricegrass and needle-and-thread that grew on a highway right-of-way immediaely adjacent to plants on a BLM grazing allotment (a cattle range used in spring and early summer, then deferred for rest of summer). Other range plant species in this "photographic quadrant" included blue grama and galleta (warm-season associate species) and a low-growing form of green Mormon tea. On this wildlife-only range, Indian ricegrass was the dominant (versus the warm-season shortgrass, blue grama that was dominant on the adjoining cattle range which was grazed in spring, mostly cool-season, and deferred in summer, the warm-season.
This range plan community was accessible to mule deer (Odocoileus hemionus) and, to leser degree, pronghorn (Antilocapra americana) as well as black-tailed jackrabbbits (Lepus californicus). These wildlife species had not availed themselves, to any substantial degree, of this abundant range feed. The right-of-way was pretty much a de facto grazing exclosure.
Bureau of Land Mnagement allotment, Monticello Field Office, San Juan County, Utah. Late July, estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 502 (Grama-Galleta). Cold Temperate Grassland142, Great Basin Shrub-Grassland 142.2, Mixed Bunchgrass-Shrub Series 142.22 (Brown et al., 1998, p. 40). Colorado Plateaus- Semiarid Benchlands and Canyonlands Ecoregion 20c (Woods et al., 2001).
Star of the transition show- Ttop-down view of blue grama on a mixed grass (blue grama the sole dominant; Indian ricegrass, needle-and-thread, and galleta, associates)-shrub savanna form of Great Plains grassland in the Colorado Plateau. This was on a highway right-of-way (hence no livestock utilization but accessibe to all wildlife species) immediately adjacent to a BLM allotment in southeast Utah. There had been zero utilization of the blue grama seen in this "photo-quadrant".
There were several cespitose plants (genotypes) of blue grama, a strictly bunchgrass species (all shoots were tillers; no stolons or rhizomes), in this wie angle-view. A close-in view of one of these plants was presented in the next photograph. Blue grama is one of the most important range grasses in North America, perhaps exceeded only by little bluestem (which is typically a tall grass in contrast to blue grama interpreted as a shortgrass species).
Bureau of Land Mnagement allotment, Monticello Field Office, San Juan County, Utah. Late July, estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 502 (Grama-Galleta). Cold Temperate Grassland142, Great Basin Shrub-Grassland 142.2, Mixed Bunchgrass-Shrub Series 142.22 (Brown et al., 1998, p. 40). Colorado Plateaus- Semiarid Benchlands and Canyonlands Ecoregion 20c (Woods et al., 2001).
Slender blue king- Portion of one of the blue grama plants introduced in the immediately preceding slide. This individual--like all of those in the preceding slide--had received zero degree of use as it was growing on a highway right-of-way (in contact with a heavily grazed BLM allotment). All of these right-of-way plants were accessible to wildlife but not to livestock. Both current season's as well as part of immediate past season's growth (including the sexual shoot with a raceme) was visible in this photograph.
It was remarked in the preceding caption that blue grama (a shortgrass species) remains one of the most important range grasses in North America. Blue grama (in tribe Chlorideae of subfamily Eragrostoideae) has the C4 photosynthetic cycle. Grasses in the Chlorideae tribe retain high nutritive content in their weathered shoots. This is partly a function of this taxon and also of the semiarid, relatively dry winter climate in which they grow. (There is generally such limited precipitation that nutrients are not readily leached or "washed out" of the herbage.
Bureau of Land Mnagement allotment, Monticello Field Office, San Juan County, Utah. Late July, estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 502 (Grama-Galleta). Cold Temperate Grassland142, Great Basin Shrub-Grassland 142.2, Mixed Bunchgrass-Shrub Series 142.22 (Brown et al., 1998, p. 40). Colorado Plateaus- Semiarid Benchlands and Canyonlands Ecoregion 20c (Woods et al., 2001).
Me and my fungus- Galleta (Hilaria jamesii) with its inflorescences infected by the fungus Ustilago aegopogonis= U. hilariicola, made for these atypical shoots of this chloroid grass growing as an assocaite species on a blue grama-dominated grassland-shrub savanna in southeast Utah (within the large Colorado Plateau physiographic province). These were last year's dead shoots. Current year's shoots had just begun to grow.
Ustilago aegopogonis infects the grain of several species. Comprehensive coverage of the smut fungi (Ustilaginomycetes) infecting the chlorocoid members of subfamily, Eragrostoideae was provided by Vanky (2004). Fourteen species of the smut fungi were described by Vanky (2004) including eight Ustilago species one of which was, in this treatment, designate as U. hilariicola (Vanky , 2004, ps. 185-186). The sori of U. hilariicola consume floral units in Hilaria species as shown in Fig. 28 of Vanky (2004, p. 186).
The author's good fortune in happening upon this phyto-pathological condition was another example of what he can only describe as "quails and mana" from Heaven (Exodus 16, King James Version). Various examples of such "miracle" finds have been presented throughout this publication. There was clearly a spiritual side to this scientific undertaking. Write it off to serendipity or testify as to the blessings of God in the wilderness.
Either way (or some of both), the smut certainly altered (almost to an indistinguishable degree) shoot morphology of galleta.
Bureau of Land Mnagement allotment, Monticello Field Office, San Juan County, Utah. Late July, estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 502 (Grama-Galleta). Cold Temperate Grassland142, Great Basin Shrub-Grassland 142.2, Mixed Bunchgrass-Shrub Series 142.22 (Brown et al., 1998, p. 40). Colorado Plateaus- Semiarid Benchlands and Canyonlands Ecoregion 20c (Woods et al., 2001).
Runt size- Dimunitive-sized plants (shoots) of green Mormon tea growing on a mixed grass-shrub savanna form of Great Plains-Great Basin Desert ecotonal grassland in the Colorado Plateau. grassland. These midget-sized shoots appeared to be of ecotypes (or, perhaps, genotypes) of Ephedra viridis that were dwarfed by more typical (larger) plants of this species. Examples of these larger forms were featured in the chapter devoted to the pinyon pine-juniper woodland, especially those seric woodlands in neighboring aeas of the Colorado Plateau insoutheast Utah.
Welsh et al. (1993, p. 30) described green Mormon tea as being highly variable in habitat (erect to spreading/sprawling) and size with heights varying from one to 15 dm.
Bureau of Land Mnagement allotment, Monticello Field Office, San Juan County, Utah. Late July.
Difference in utilization- Two views (landscape-scale, first or upper slide; local-scale or "nested" sub-plot, second or lower slide) oa a mixed grass-shrub savanna form of an ecotonal Great Plains mixed prairie-Great Basin Desert grassland that developed in the Colorado Plateau. Range on the left was part of a highway right-of-way that was accessible only to (and hardly used by) wildlife whereas range on the right was heavily grazed in spring to early summer by beef cattle (as well as being open to wildlife).
The contrast was more a feature of utilization (degree of use) and secondly a feature of species composition, but the cool-season Indian ricegrass was dominant on the right-of-way (de facto livestock exclosure) whereas the warm-season blue grama was dominant on the heavily grazed cattle range. Other grass species, needle-and-thread and galleta being the most important, were similar between the two grazing treatments. Shrub species were also similar but winterfat, especially, and fourwing saltbush, to lesser degree, had greater cover on the beef cattle-excluded right-of way.
Bureau of Land Mnagement allotment, Monticello Field Office, San Juan County, Utah. Late July, estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 502 (Grama-Galleta). Cold Temperate Grassland142, Great Basin Shrub-Grassland 142.2, Mixed Bunchgrass-Shrub Series 142.22 (Brown et al., 1998, p. 40). Colorado Plateaus- Semiarid Benchlands and Canyonlands Ecoregion 20c (Woods et al., 2001).
First of the Cardinal Principles- Two views (first was at farther camera distance) of a fenceline contrast of a mixed grass-shrub savanna form of transition Great Plains mixed prairie-Great Basin Desert grassland that developed in the Colorado Plateau (in southeast Utah). Range vegetation on the left was on a highway right-of-way from which caattle were excluded and on which the naive ruminants, mule deer and pronghorn, appeared to make little use (in effect, a de facto exclosure). Range vegetation on the right was a heavily grazed cattle range used in spring and early summer and deferred during rest of the summer growing season.
The obvious contrast was more due to degree of use (utilization) than to plant species composition, but the warm-season, eragrostoid blue grama was dominant on the heavily grazed cattle range and the cool-season, festucoid Indian ricegrass was dominant on the de facto exclosure. The shrubby chenopods, winterfat and fourwing saltbush, had greater cover on the highway right-of-way. This was more so for winterfat. It was not known how much of this difference was due to cattle and/or mule deer or pronghorn because even though cattle and not wildlife were excluded, there was no observed browsing use on these generally palatable shrubs growing on the right-of way which, again, appeared to serve as a de facto or artifact exclosure for both livestock and native ruminants.
The gray shrub in center foreground (to immdiate left of the fence) was a female winterfat. The leached-out amber straw (dead grass shoots) were Indian ricegrass (first in foliar cover) and needle-and-thread (second in foliar cover). Dark green herbage was blue grama (galleta was just starting to green-up). The cespitose habit of all these bunchgrass species was much in evidence in all of these phtographs.
Degree of Use (utilization), which is the primary result of Stocking Rate, is the first and most important of the Four Cardinal Principles of Range Management. Season of Use is another of the Cardinal Principles. Both of these Crdinal Principles were illustrated poignantly in this series of slides.
Bureau of Land Mnagement allotment, Monticello Field Office, San Juan County, Utah. Late July, estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). SRM 502 (Grama-Galleta). Cold Temperate Grassland142, Great Basin Shrub-Grassland 142.2, Mixed Bunchgrass-Shrub Series 142.22 (Brown et al., 1998, p. 40). Colorado Plateaus- Semiarid Benchlands and Canyonlands Ecoregion 20c (Woods et al., 2001).
Southern Great Plains-Colorado Piedmont Mixed Prairie
173. Galleta-blue grama plains and mesa grassland in drought- Appearance of High Plains (Llano Estacado) mixed prairie in prolonged, severe drought and under current overuse. Galleta was the obvious dominant species with blue grama, buffalograss, western wheatgrass, and sand dropseed all microsite associate species and in that relative mean (overall range community) order of abundance. This range had absolutely no mesquite, but the native plains pricklypear (Opuntia polyacantha)-- seen as small isolated patches in foreground-- had begun to appear at density and cover of an invader (greater amounts than in climax vegetation). It must be borne in mind, however, that overuse of grass had exposed pricklypear prominently. Nonetheless, there was virtually no doubt but what this range was probably being mismanaged-- to some detriment of both range and cattle. Excessive degree of use (overuse= removal by grazing animals of excessive portions of current season's leaves and stems that if conitinued will lead to overgrazing) was indeniable.
The most immediate incontrovertible evidence of current overuse was grazing of young, growing plants of broadleaf milkweed (Asclepias latifolia) by cattle. A. latifolia is one of the more toxic plants on High Plains ranges (perhaps because there are not as many poisonous plant species in this region as in some of the more botanically diverse adjoining ones like the Trans Pecos Basin and Range and Edwards Plateau). Livestock poisoning by broadleaf milkweed is enough of a problem that it was routinely covered in standard textbooks and Agricultural Experiment Station-Extension publications (eg. Sperry et al., undated). In the example shown here it was human management of range and cattle that resulted in milkweed consumption. There was no evidence of toxicity to cattle: apparently quantities eaten were below toxic levels (at time of photograph). If current overstocking does not result in overgrazing (range retrogression due to prolongued overuse) with corresponding damage to basic range resources like soil and watershed features and/or economic losses in livestock (in excess of that from emergency feeding), such periods of overuse cannot automatically be labeled as mismanagement. Cows and calves grazing this range remained in thrifty condition and as the grass species were in semi-dormancy the range was not being severely abused. The situation was that there were indications that current grazing management was allowing invasion by plains pricklypear. More frequent movement of cattle to different pastures or even culling of lower-producing cows might well be more economical in the long run.
Examples of broadleaf milkweed were presented below in this Mixed Prairie portion. The large Brangus cow beside the cholla indicated size of some of these cactus plants.
Guadalupe County, New Mexico. Early estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Gramagrass-Buffalograss). SRM 705 (Grama-Galleta). Grama "Short-Grass" Series of Brown et al (1998). Southwestern Tablelands- Conchas/Pecos Plains Ecoregion, 26n (Omernik and Griffith, 2006).
174. Sward of plains and mesa mixed prairie in drought and without cattle grazing- Details of galleta-blue grama-buffalograss-western wheatgrass-sand dropseed (all are visible) community shown in the preceding photograph except that grass shown in this photograph was not grazed. Vegetation seen here was immediately adjacent to but outside the fence that enclosed the currently overused range of plains and mesa mixed prairie. Difference in degree of use was obvious, but there was little difference in species composition except for absence of broadleaf milkweed and less cover of plains pricklypear. Grazing by cattle had apparently contributed to an increased number of plant species and a somewhat different plant "mixture" (ie. cattle grazing apparently increased biological diversity). Is this sort of increased biodiversity "good" or "bad"?
Western wheatgrass photographed here was in anthesis. Western wheatgrass inside the pasture shown in the preceding slide was grazed to a stubble height of less than two inches and there were no flowering shoots. In other words, even in severe, early season drought cool-season grasses were in the process of producing seed-- where they were not "grazed into the ground".
Degree of use is determined largely by the stocking rate. Proper degree of use (proper stocking rate) is the first and most important of the Four Cardinal Principles of Range Management.
Guadalupe County, New Mexico. Early estival aspect, June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Gramagrass-Buffalograss). SRM 705 (Grama-Galleta). Grama "Short-Grass" Series of Brown et al (1998). Southwestern Tablelands- Conchas/Pecos Plains Ecoregion, 26n (Omernik and Griffith, 2006).
175. Relict plains-mesa mixed prairie (shrub steppe form)- Although this semiarid grassland in the Datil section of the Colorado Plateau was enduring a severe to exceptional drought and in semi-dormancy it was the potential natural vegetation. These two photographs showed the species composition and physiogonomy of a climax mixed prairie grassland with a shrub component that appeared almost as a shrub-grassland savanna. The climax dominant shrub was fourwing saltbush. There was an occasional broom snakeweed (an all-too-common invader on adjacent range), but the vegetation here was in "mint condition". On the extremely sandy soil of this range site Indian ricegrass was the clear dominant with sand dropseed, plains lovegrass, blue grama, and sideoats grama all abundant species and growing as mixed localized "mini-communities". Sand dropseed dominated some microsites. Blue grama, the dominant species of this general regional (monoclimax or ecoregion dominant) was never a local dominant on this sandy range. Galleta was not present (or if missed, it was but a trace).
Cibola County, New Mexico. Early vernal aspect (Extreme to Exceptional drought), June. FRES No. 38 (Plains Grassland Ecosystem). K-47 (Gramagrass-Galleta Steppe). Variant of SRM 502 (Grama-Galleta); SRM 705 (Blue Grama-Galleta) occurs to the east of the 502 rangeland cover type but resembles it rather closely.
Dick-Peddie (1993, p. 104) described this and the mixed prairie example in the succeeding slide, Great Plains grassland-Great Basin grassland transition, as part of the plains and mesa grassland in which blue grama was a common denominator but often co-dominant with galleta on mesas in the northern half of New Mexico. He specified: "On fine-textured soils in the north and northwest, Indian ricegrass (Oryzoides hymenoides) may share dominance with blue grama, or communities can be found with New Mexico feathergrass (Stipa neomexicana) and needle-and-thread (S. comata) sharing dominance with blue grama" (Dick-Peddie, 1993, p. 119). Arizona/New Mexico Plateau- Semiarid Tablelands Ecoregion, 22j (Omernik and Griffith, 2006).
Phenological/species compositional note: photographs of rangeland cover types Wheatgrass-Grama-Needlegrass (SRM 608) & Wheatgrass-Needlegrass (SRM 607) taken in June 2008 gave an atypical representation of these types. A late spring (abnormally cold and wet) was a boon for needlegrass species and "hard scramble" growing conditions for wheatgrass species. Although slides were taken in early summer, phonological stages of most species— especially western wheatgrass—were those typically taking place much earlier in the growing season. Aspects, especially aspect dominance, structure, and relative composition of these mixed prairie communities were generally those of vernal societies at a time in growing season when estival aspects and societies normally would have predominated. Again, western wheatgrass in particular was underrepresented from average composition (based on relative cover), structure, and overall physiogonomy. Also, in early summer blue grama was still in early vegetative stages of phenology so as to be vastly underrepresented from the standpoint of cover dominance. Simply put, photographs were of the vernal rather than estival societies of these types.
These clarifying notes made, it should also be stressed that these photographs did display clearly the dominance of needle-and-thread (Stipa comata) which has traditionally been regarded as the overall first defining co-dominant of the mixed prairie (Stipa-Sporobolus) association (Dodd in Gould and Shaw, 1968, 1983, ps. 349-351) which traced back to the seminal knowledge of Clements (1920, ps. 122, 135-138) and Weaver and Clements (1938, ps. 523-524). Incidentially, more recent interpretations appeared to have placed needle-and-thread "second in command" to blue grama and/or western wheatgrass as can be seen in titles of potential natural vegetation by Kuchler (1964, 1966) and the Society for Range Management Shiflet (1994) shown below. The photographs presented below--even allowing for aspect dominance and an estival aspect--suggested that initial interpretations by Clements (1920) and Weaver and Clements (1938) and subsequently by Dodd (in Gould and Shaw, 1968, 1983) were closer to the mark.
Location note: a transition (ecotonal) grassland between plains-mesa mixed prairie (SRM 705, Blue Grama-Galleta) and the most xeric grama-galleta-shrub form (variant of range type, SRM 502, Grama-Galleta)--maybe a hybrid of these two rangeland cover types--of semidesert grassland was presented at end of Chihuhuan Region section of Semidesert Grasslands, Range Types of North America.
Western wheatgrass (Agropyron smithii) is one of the most widely distributed midgrass species over much of the Great Plains. Its biological (species) range extends from (Barkworth et al., ). Western wheatgrass is also a species with almost as wide a distribution of scientific names (binomials). It was explained in the Names section of Introduction of Range Types that over course of the last quarter the genus of western wheatgrass century had changed numerous times including Elytrigia, Pascopyrum, and Elymus (besides Agropyron).
More pertinent to range vegetation is the situation or phenomenon that western wheatgrass occurs in a number of range plant communities including consociations (of nerly single-species stands) down to being a minor species in diverse grassland communities. Western wheatgrass occurs as a dominant in five rangeland cover types recognized by the Society for Range Management (Shiflet, 1994): SRM 606, SRM 607, SRM 608, SRM 609, and SRM 610 with this latter being "dominated almost exclusively by western wheatgrass" (Shiflet, 1994). Given that western wheatgrass is a midgrass SRM 610 (by definition more a population than a community) is true rather than mixed prairie.
In the seminal descriptions and comparisons of true and mixed prairies (Clements, 1920, p.122, 137) western wheatgrass and needle-and-thread were shown as the only tww species that formed consociatiosn in both of these grassland associations. Hence, distinction between true and mixed prairie on basis of species make-up can be tenuous and in the eyes of the beholding plant ecologist.For this reason samples of western wheatgrass-dominated grasslands were included in the two Grassland chapters, True Prairie and Mixed Prairie.
176. Western wheatgrass in all its splendor- South slope hillside in Southern Hihgh Plains that was a "pure" stand of western wheatgrass. This consociation of western wheatgrass was was atypical to say the least. The soil was a deep clay with unusually high water-holding capacity that was able to override what would otherwise been the all-powerful impact of a dry south slope resulting in blue grama and buffalograss.
This steep hillside (by High Plains standards) was located immediately above a swale form of range site (next set of slides below). Predominance of western wheatgrass in the swale extended outward and upward resulting in a single-species of midgrass-dominated mixed prairie. In fact, the only other plant species of any consequence besides western wheatgrass was stink or buffalo gourd (Cucubita foetidissima). There were a few isolated plants of cheatgrass at margins of this stand.
Gray County, Kansas. Late June (early estival aspect; prebloom to early bloom stage of western wheatgrass). K-61 (Wheatgrass-Grama-Buffalograss). SRM 610 (Wheatgrass). Should be a Wheatgrass Series, say, 142,14 of Plains Grassland biotic community 142.1 of Cold Temperate Grassland 142 of Brown eta al (1998, p. 40). Western High Plains- Flat to Rolling Cropland Ecoregion, 25d (Chapman et al., 2001).
177. Fertile landscape of a mixed prairie- Landscape-scale view of mixed prairie in Southern High Plains taken from mid-slope (foreground) extending across a swale site (far midground) back to mid- and upper slope behind swale (distant background). Upper slope and summit of hill was presented in the immediately preceding two-slide set. Details of range vegetation in the swale were shown in succeeding slides.Alignment of range sites and distinctive (though quite similar) range plant communities along slope from swale to hill summit was a catena or toposequence which was defined/described above.
The general (overall) range plant community along this catena was a western wheatgrass-buffalograss-blue grama mixed prairie with there being consociations (single-species stands) of western wheatgrass on portions of swale with deeper soils and, strangely enough, on parts of some slopes and hilltops. The native annual grass, little barley, was common in local patches where the swale met the lower hill slope. A western wheatgrass consociation was visible in foreground. Behind this local range vegetation (midground back to prominent side slopes of swale) western wheatgrass and buffalograss were co-dominants.
This range was being grazed by typical size black baldy cows and calves.
Gray County, Kansas. Late June (early estival aspect; prebloom to early bloom stage of western wheatgrass). K-61 (Wheatgrass-Grama-Buffalograss). SRM 609 (Wheatgrass-Grama) and SRM 610 (Wheatgrass). Should be a Wheatgrass Series, say, 142,14 of Plains Grassland biotic community 142.1 of Cold Temperate Grassland 142 of Brown eta al (1998, p. 40). Western High Plains- Flat to rolling Cropland Ecoregion, 25d (Chapman et al., 2001).
178. Swaled with pride- Swale in Southern High Plains co-dominated by western wheatgrass and buffalograss with little barley as associate. The latter is a native annual grass. This view was from the upper bank of the swale that was introduced in the immediately preceding photograph of the gently hill-swale landscape. Some parts of the swale as well as hill sides and summits were consociations of western wheatgrass. Examples of western wheatgrass consociations on hills were shown above.
This range was being grazed at moderate stocking by lactating black baldy cows (about 900-1000 pounds in body condition score of about 6) and approximately 350-450 pound calves. There was a considerably high porportion of ungrazed tillers on western wheatgrass.(An interesting fenceline contrast of this range and ungrazed hihgway right-of-way was shown below.)
Gray County, Kansas. Late June (early estival aspect; prebloom to early bloom stage of western wheatgrass). K-61 (Wheatgrass-Grama-Buffalograss). SRM 609 (Wheatgrass-Grama). Should be a Wheatgrass Series, say, 142,14 of Plains Grassland biotic community 142.1 of Cold Temperate Grassland 142 of Brown eta al (1998, p. 40). Western High Plains- Flat toRolling Cropland Ecoregion, 25d (Chapman et al., 2001).
179. Swell swale on the High Plains- Sward of a westrn wheatgrass-buffalograss mixed prairie that developed on a swale site in the Southern High Plains. Both of these co-dominant species are sod-forming grasses; western wheatgrass being rhizomatous and buffalograss, stoloniferous. While there were some scattered plants of blue and even hairy grama up on the sides of this swale the swale environment, including greater area of surrounding slopes, was a western wheatgrass-buffalograss climax commnity in which the associate species was the native, annual, festucoid grass, little barley. It was revealing of proper stocking (proper degree of use) that there was an annual grass component of the native little barley rather than the naturalized, invasive, Eurasian bromes, cheatgrass and/or Japanese chess. It was revealing of this swale range site and its range plant community that blue grama was not a major component.
Clarification and suggestion: the closest rangeland cover type recognized by the the Society for Range Management (Shiflet, 1994) that could be applied to range vegetation described at this juncture was SRM 609 (Wheatgrass-Grama). That dominance type does indeed exist, but so does a Western Wheatgrass-Buffalograss dominance type represented by examples presented here. In fact, across much of the Southern High Plains the wheatgrass-buffalograss type is much more common than wheatgrass-grama type on clayey, mesic range sites. This is because buffalograss is better adapted to certain dense clay habitats--such as widely distributed swale sites of various forms--than is blue grama , It was suggested that a Western Wheatgrass-Buffalograss range type be included in any further editions of rangeland cover types published by the Society for Range Management.
Beginning students should note carefully the appearance of the sward of this properly grazed mixed prairie that consisted of a midgrass, western wheatgrass, and a shortgrass species, buffalograss. Notice that the more vulnerable midgrass had not been grazed out and replaced by a short sod of the more grazing-tolerant shortgrass. The botanical composition of the climax range vegetation was being maintained. This was an exampole of sustainable agriculture. This range exemplified the fundamental concept of sustained yield. This cattleman obviously knew that the profitablility of his cow-calf herd depended upon the forage crop they grazed. The vegetation on this range showed that this stockgrower understood--as judged by the living results of his grazing management--that range feed was his crop while feeder calves were his commodity. Beef cttle were the "harvestor" and "converter" of the crop into the marketable product. This straightforward situation is a foundation of sucessful ranching.
Gray County, Kansas. Late June (early estival aspect; prebloom to early bloom stage of western wheatgrass). K-61 (Wheatgrass-Grama-Buffalograss). SRM 609 (Wheatgrass-Grama). Should be a Wheatgrass Series, say, 142,14 of Plains Grassland biotic community 142.1 of Cold Temperate Grassland 142 of Brown eta al (1998, p. 40). Western High Plains- Flat to rolling Cropland Ecoregion, 25d (Chapman et al., 2001).
180. Fenceline contrst on a mixed prairie- Grazed and ungrazed plant community of mixed prairie on a swale site in the Southern High Plains. This was the cow-calf range described above (right) and the adjoining ungrazed highway right-of way (left). The properly grazed grassland was a western wheatgrass-buffalograss mixed prairie with little barley as the major associate and with sparse cover of blue grama and, even lesser cover of, hairy grama. The ungrazed side of the fenceline was dominated by hedge bindweed (Convolvulus sepium) that was obviously overrunning western wheatgrass and buffalograss, the climax co-dominants of this swale range site. This comparison "photoquadrant" was in the center of the channel (bed) of the swale. This more mesic microsite was the most favorable habitat for hedge bindweed.
This was an example where livestock grazing was beneficial to the range. Cattle had obviously reduced plant size and cover on the grazed range so that western wheatgrass and buffalograss were clearly of greater relative proportions of the range polant community in the pasture than in the road side of this natural swale. One electrified wire made the difference. Hedge bindweed is a naturalized Eurasian perennial that is a dreadful weed across broad regions of North America. It is aggressive, trailing, herbaceous vine that is, however, quite palatable to most herbivores, even to grass-preferring species like cattle. Common observations-- like the example shown here--have long indicated that grazing reduces vigor, cover, etc. of this noxious pest. Biological control is one fairly effective of controlling this weed. (By the way, observant viewers will have seen that cattle had been grazing under this single-wire electric fence to the extent of f their heads and necks to get the hedge bindweed on the other side. Bindweed was obviously more palatable than the native grasses or, alternatively, the cattle just chose some more variety in their diets)
Gray County, Kansas. Late June (early estival aspect; prebloom to early bloom stage of western wheatgrass). K-61 (Wheatgrass-Grama-Buffalograss). SRM 609 (Wheatgrass-Grama). Should be a Wheatgrass Series, say, 142,14 of Plains Grassland biotic community 142.1 of Cold Temperate Grassland 142 of Brown eta al (1998, p. 40). Western High Plains- Flat to rolling Cropland Ecoregion, 25d (Chapman et al., 2001).
181. The relict is the standard- Ungrazed sward of western wheatgrass-buffalograss mixed prairie on highway right-of-way adjacent to a range of this same climax vegetation grazed by black baldy cows and their calves. This exclosure was on the upslope section of a swale range site whereas the preceding photograph that was a comparison of grazed and ungrazed range vegetation was in the more mesic bottom of the swale.
Botanical composition of range vegetation in the exclosure (ungrazed road right-of-way) was the same as that of the grazed range except for the presence of more forbs on the ungrazed range. These native forbs were wild alfalfa or slender scurfpea (Psoralea tenuiflora),wavyleaf thistle (Cirsium undulatum), and plains prickly poppy (Argemone polyanthemos). Obviously all three were preferred--at least on this range site and by this (or past) cattle herds--because these three forb species were not found on the grazed portion of the range. The range had not been "weed sprayed" as proven by presence of the forb plants seen here that were within a few feet of the fence, a distance too close to avoid droplets of herbicide.
Gray County, Kansas. Late June (early estival aspect; prebloom to early bloom stage of western wheatgrass). K-61 (Wheatgrass-Grama-Buffalograss). SRM 609 (Wheatgrass-Grama). Should be a Wheatgrass Series, say, 142,14 of Plains Grassland biotic community 142.1 of Cold Temperate Grassland 142 of Brown eta al (1998, p. 40). Western High Plains- Flat to rolling Cropland Ecoregion, 25d (Chapman et al., 2001).
182. Forbs for friends- A swale range site dominted by western wheatgrass with buffalograss as associate species. Accompanying species were wavyleaf thistle (Cirsium undulatum) and wild alfalfa or scurfpea (Psoralea tenuifolia).
Gray County, Kansas. Late June (early summer) with various stages of phenology for various species as for example pre-bloom for scurfpea, peak-bloom in wavyleaf thistle, immediate post-bloom in western wheatgrass, and post grain-shatter for buffalograss.
183. Bottomland range site upslope from a playa- A range plant community of western wheatgrass, Illinois bundleflower (Desmanthus illionensis), and showy milkweed (Asclepias speciosa) had developed just beyond the outer margin of the unique range vegetation around a playa. This was one of many range types (and their variants) that comprise the general subformation of mixed prairie grassland. This range plant community was a general consociation of western wheatgrass with large patches of Illinois bundleflower and plains or showy milkweed dispersed throughout in more mesic microhabitats. It was on the Colorado Piedmont section of the Gret Plains physiographic province.
Otero County, Colorado. Late June (early estival aspect; peak anthesis stage of western wheatgrass). K-61 (Wheatgrass-Grama-Buffalograss). SRM 610 (Wheatgrass). Should be a Wheatgrass Series, say, 142,14 of Plains Grassland biotic community 142.1 of Cold Temperate Grassland 142 of Brown eta al (1998, p. 40). Western High Plains- Flat to rolling Cropland Ecoregion, 25d (Chapman et al., 2001).
184. Natural pasture of a grass and legume- Western wheatgrass and Illinois bundleflower formed a native "grass-legume mix" of mixed prairie on the Colorado Piedmont just west of the Southern High Plains. A grass-legume mixture has been a forage crop "ideal" or "standard" of grassland agriculture for decades. Legumes are extremely difficult to maintain on pastures and, even more so, on ranges because almost all animals prefer the legumes so that under all but the most judicious grazing and cultural management the legumes are grazed out leaving the grass species. Soil pH and nitrogen must be skillfully managed if legmues are to be maintained. Otherwise the pasture--natural or agronomic--becomes a grassland or, on tame pasture, a single-species stand of grass. On the natural pasture of range manipulation of grazing is usually the only management practice(s) possible given the economic infeasiblility of applying fertilizers and soil amendments like lime.
The natural "mixture" of (co-dominance by) westrn wheatgrass and Illinois bundleflower shown here was in the exclosure formed by a state-maintained fence at edge of a highway right-of-way. Relatively light grazing would be necessary to maintain viable populations of Illinois bundleflower within an otherwise "solid" or"pure" stand of western wheatgrass. Regardless, these "photoplots" presented the potential natural (climax) vegetation for this lowland range site.
Otero County, Colorado. Late June (early estival aspect; peak anthesis stage of western wheatgrass). K-61 (Wheatgrass-Grama-Buffalograss). SRM 610 (Wheatgrass). Should be a Wheatgrass Series, say, 142,14 of Plains Grassland biotic community 142.1 of Cold Temperate Grassland 142 of Brown eta al (1998, p. 40). Western High Plains- Flat to rolling Cropland Ecoregion, 25d (Chapman et al., 2001).
185. Stand of western wheatgrass- Closer-in-view of a consociation of western wheatgrass. This colony may well be many shoots of a single plant of this rhizomatous species. This is another example of a clonal organism in which each shoot is a module, clone or ramet of the genetic individual known as a genet. Peak standing crop: grains are in hard dough stage. Oldham County, Texas. June.
186. Standing tall and very thick- Shoots of rhizomatous western whestgrass at peak standing crop. This is a still-yet closer-in-view of the stand shown in the preceding slide. A small (but very sexually repoductive) cheatgrass (Bromus tectorum) plant held its own to clomplete its life cycle in the foreground. This is a good example of sexual vresus asexual reproduction in an annual versus a perennial grass, and of an annual introduced (from Eurasia) invader versus a perennial native decreaeer. Western wheatgrass "hedged its bets" by using both asexual (numerous shoots, modules or ramets, from rhizomes) and sexual (grain production in its many florets as were shown below). Range Management students should familarize themselves with the concept of adaptative "plant strategies" developed by Grime (1979).
Oldham County, Texas. June. Peak standing crop; hard dough stage.
187. Western wheatgrass- An example of western wheatgrass showing the characteristic growth pattern produced by clonal growth and development of "daughter plants" in this rhizomatous species. Lincoln County, Colorado. June.
188. Spike inflorescence of western wheatgrass- The spike arrangement of spikelets is a key tribal characteristic of the Hordeae (= Tritaceae). Erath County, Texas. Mid-May; anthesis.
189. Close-up of spike portions of western wheatgrass- Detail of western wheatgrass spikes showing individual florets in spikelets.Oldham County, Texas. June.
Note on location and organization: numerous other examples of western wheatgrass-dominated grasslands (including western wheatgrass consociations) were presented in the chapter, Mixed Prairie-- Northern Great Plains.
190. Transition zone mixed prairie- Mixed prairie dominated by needle-and-thread, blue grama, and western wheatgrass in lower foothills of the Southern Rocky Mountains in a patchwork pattern of range vegetation with true mountain mahogany (Cercocarpus montanus) shrubland. This scrub range type was treated in the Mountain Scrub chapter under Shrublands. To reduce confusion the mountain mahogany scrubland was not described here.
Additional important--at least locally so--grasses included Junegrass (Koeleria cristata= K. pyramidata), slender wheatgrass (Agropyron trachycaulum), bluebunch wheatgrass (A. spicatum), Sandberg's bluegrass (Poa secunda), big bluegrass (P. ampla), Canby's bluegrass (P. canby), plains bluegrass (P. arida), squirreltail (Sitanion hystrix), some Indian ricegrrass (Orysopsis hymenoides), occasional plants of little bluestem (Andropogon scoparius=Schizachyrium scoparium), local stands of cheatgrass (Bromus tectorum), and scattered plants of the naturalized, Eurasian crested wheatgrass (Agropyron cristatum).
Forbs were limited but the most common one at this season was whiskbroom parsley (Harbouria trachypleura). Shrubs, other than true mountain mahogany at grassland-shrubland contact, were absent except for an occasional plant of fringed sagewort (Artemisia frigida).
Laramie County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Southern Rockies- Mid-Elevation Forests and Shrublands Ecosystem, 21c (Chapman et al., 2003).
191. Sward of foothill mixed prairie- "Photo-quadrant" of mixed prairie in an area of transition from western edge of Great Plains to foothills of the Southern Rockies. Needle-and-thread was the overwhelming dominant with western wheatgrass (which was underrepreented in this particular spring-summer period) and blue grama (early in the year for full vegetative expression of it) the associate species. Other grasses included Junegrass, slender wheatgrass, bluebunch wheatgrass, Indian ricegrass, Sandberg's bluegrass, big bluegrass, Canby's bluegrass, plains bluegrass, little bluestem, and, as always, cheatgrass.
Principal forb at this season was whiskbroom parsley. Shrubs were absent except for infrequent fringed sagewort (when this is interpreted as a shrub). This was grassland in purest sense of the term, and it was grassland in Excellent range condition class.
Laramie County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Southern Rockies- Mid-Elevation Forests and Shrublands Ecosystem, 21c (Chapman et al., 2003).
This next section of mixed prairie range presented four ranges of the needle-and-thread--western wheatgrass--blue grama grazing type (SRM 608) in Excellent, Good, Fair, and Poor range condition class. These four pastures were photographed on the same day (2 June) within about three hours and 25 miles of each other (three pastures were in Niobrara County, Wyoming and one range was in Sioux County, Nebraska). Photographs were taken with a wide-angle (28mm) lense so there were several range sites in each landscape-scale photograph, but for comparative purposes photographs featured the same or similar range sites in their foregrounds which was flatter rangeland on benches and not tops or sides of hills. None of the rangeland presented in these slides was near enough to a sacrifice area to bias views of range vegetation.
Key feature of this range type- The "mixed" characteristic of this form, this rangeland cover type, of mixed prairie was through dominance by three midgrass species. There was not a tallgrass component--at least not as a dominant species--in this type-level range plant community. This was in contrast to the Wheatgrass-Bluestem-Needlegrass rangeland cover type (SRM 606) which had sand bluestem as a dominant tallgrass species. The needle-and-thread--western wheatgrass--blue grama type did,however, include both dominant cool-season and warm-season species. This contrasted with the Wheatgrass-Needlegrass rangeland cover type (SRM 607 ) which lacked a warm-season dominant.
192. Mixed prairie in all its glory; first of a comparison- Central Great Plains grassland dominated by needle-and-thread, blue grama, and western wheatgrass with Indian riecgrass and threadleaf sedge (Carex filifolia) associate species. Forbs included crested tongue penstemon or crested beardtongue (Penstemon eriantherus), silvery lupine (Lupinus argenteus), scarlet globemallow (Sphaeralocea coccinea), and a speciimen of an unknown Astragalus species.
This range plant community did not have a particularily rich flora, but it was in mint condition. This was textbook climax mixed prairie of the central grassland formation, grassland like it was when God had it by Himself. A wll-earned stewardship salute to this private landowner.
Note: this range was being grazed at a light degree of use. It was photogrphed at peak standing crop for cool-season perennial grasses (ie. vernal society of the range plant community) which automatically overrepresented needle-and-thread, western wheatgrass, indian ricegrass, and threadleaf sedge relative to warm-season species like the third dominant blue grama. Viewers should not confuse views or perceptions of vegetation resulting from utilization (degree of use) with those due to species composition. This must also be borne in mind when viewing and comparing ranges shown below.
Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003).
193. Sward of western mixed prairie in mint condition- Two 'photo-plots" of the sward of the Excellent condition class range of western mixed prairie presented in the immediately preceding pair of photographs. In the first of these "plots" needle-and-thread and western wheatgrass, which along with blue grama, were the overall dominants, made up the cover in left background while threadleaf sedge dominated most of the rest of this sample of range vegetation. In the second "plot" threadleaf sedge was the local dominant with western wheatgrass and needle-and-thread in control of microsites in the background. Main forb was fringed sagewort or fringed sagebrush. There were a few individuals of the Eurasian weed, goat'sbeard (Tragoypogon dubius).
Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003).
194. Western mixed prairie; second of a comparison- Another range in the western Central Great Plains comprised of needle-and-thread, western wheatgrass, and blue grama. Like the preceding range used as an example of this cover type (two sets of paired photographs just shown) needle-and-thread was dominant and conspicuous. (Recall from introduction to this set of slides that it had been a near-perfect for Stipa comata.) Unlike the first example that was Excellent condition class range the one shown here and in the next photograph, was in Good condition class. This range had been graazed with a greater degree of use (low end of moderate) than the range presented immediately above, but the meaningful difference between between these two ranges was in species composition not utilization.
The range shown here and in the follow-up view of the sward had much less western wheatgrass and blue grama and instead had Sandberg's bluegrass as the associate species. This pasture also had considerably greater cover of cheatgrass. There was also slightly more fringed sagewort on the range shown here. Other species included plains bluegrass, threadleaf sedge, and even Indian ricegrass, but cover (basal and foliar) of these--even allowing for greater degree of use--was substantially less than on the Excellent condition range.
Range sites were similar, at least enough for comparison. No, the difference in species composition had been previous--not current season--grazing management.
Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003).
195. Sward of mixed prairie in Good condition- A "photo-plot" of range vegetation on the Good condition class range introduced in the immediately preceding slide. Needle-and-thread was still dominant and there was still some cover of decreaser forage speciees like Indian ricegrass and threadleaf sedge. This was substantially less than on the Exeellent condition class range presented and described above. There was also considerably greater incidence and cover of cheatgrass at local scale (although little was shown here). Incidence of miscellaneous forbs (mostly commposites) was also greater on this Good than on the Excellent condition range.
Degree of use of the range overall was in the moderate category.
Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003).
196. Western mixed prairie; third of a comparison- A third range of the needle-and-thread-western wheatgrass-blue grama type of mixed prairie in the Central Great Plains. This one was under high fence for the explicit purpose of grazing North American buffalo (Bison bison). Unfortunately for this former reigning ruminant of the central grasslands of the plains this range was in Fair range condition class. Needle-and-thread, generally the defining dominant of mixed prairie in this region, was still the dominant perennial grass. At least this was the situation on this range at end of the growing season for cool-season species (period of the vernal society) and prior to main portion of growth for blue grama, the regional warm-season dominant.
Even though needle-and-thread was the dominant native grass, the dominant range plant on this range (the one with greatest cover, density, and biomass) was the Mediterranean, weedy annual cheatgrass. Cheatgrass was conspicuous as the reddish or off-color purple coloration in the foreground. Naturalized and self-seeded crested wheatgrass was also present as scattered individuals on the degraded range featured in the foreground. On hills in the background there was much less cheatgrass and, in fact, that range vegetation was Good to Excellent condition range like that shown for the "mint" condition range used at start of this comparison. Note, however, that range vegetation on hillsides and hilltops was not compared in any of these photographs. Rather it was vegetation on benches and on rangeland with less relief that was used for comparative pruposes of all ranges. Range vegetation that was presented for purposes of comparison as to species composition was on similar slopes, aspects, and as close to comparable range sites as possible among available pastures.
Likewise, the pasture shown here had degree of use (light) similar to that of the first pasture, the "mint" condition range, and lighter defoliation than that of the previous range that was in Good condition class and had moderate degree of use at time of photograph. It was obvious that past grazing had been considerably greater (heavier degree of use or utilization) on the flatter rangeland (foreground) than on hillsides of the range featured here. This may have been attributable to grazing by cattle in the recent past with buffalo being a recent reintroduction. Evidence of this possibility was the "brand new" high game fence that enclosed this range. It would be an almost foregone conclusion or assumption that beef cattle had been the major species of range animal before bufffalo had been restocked on their former range by the present landowner who quite obviously "had more money than he knew what to do with".
Regardless, this was an example of needle-and-thread dominated mixed prairie in Fair range condition class that can be compared to those of the same range type (and similar range site) in Excellent and Good condition class (above) and Poor condition class (coming up next).
Niobrara County, Wyoming. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2003).
197. Western mixed prairie; fourth of a comparison- A fourth range of the needle-and-thread-western wheatgrass-blue grama type of mixed prairie in the western Central Great Plains. Can there be any doubt that this pathetic degraded example was in Poor condition class? The green (and gnawed down) spots were remains of needle-and-thread and western wheatgrass. The silvery bunches were fringed sagewort. Reddish brown patches were local stands of cheatgrass. The one taller, green bunch of grass was crested wheatgrass which, incidentially, attested to the low palatability of this introduced and naturalized range grass compared to palatability of native grasses like needle-and-thread and western wheatgrass. There was also Sandberg's and plains bluegrasses along with the native annual, sixweek's fescue (Festuca octoflora).
Degree of use on palatable decreaser species was relatively high or close under heavy grazing. Obviously there was little grazing use made of fringed sagewort and invaders like cheatgrass. This Poor (and sadly unfortunate) range had a long history of overuse (obviously stretching over a number of years) so that the misuse had gone to the state of overgrazing. This range was in such a state of degradation (retrogression of range vegetation on this sere) that it almost required a "crime scene uinvestigator" to identify "species of the corpse". Compare the stewardship of this landowner (or renter) and, maybe, previous graziers to that of the good and faaithful stewards wisely using the Excellent and Good condition class ranges presented previously.
Sioux County, Nebraska. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it. Western High Plains- Sandy and Silty Tablelands Ecosystem, 25g (Chapman et al., 2001).
Dog town- The black-tailed prairie dog (Cynomys ludovicianus), a fossorial (Latin, fossor, translated as digger) rodent, was arguably the dominant range animal (perhaps more so than the American buffalo or bison) over much of the Great Plains and parts of adjoining physiographic provinces. It is a native mammal and the source of many comments, observations, and conjecture among frontiersmen.
The black-tailed prairie dog is a highly social and fecund mammal that forms extensive colonies known as towns. Early accounts reveal prairie dog towns reveal of immense dimensions. Merrian (1001) estimated tht one blact-tailed prairie dog town in Texxas covered 25,000 square miles. The black-tailed prairie dog is a strict herbivore and one--from human perception--with a ferocious appetite for grass that could be eaten by livestock that have value in the marketplace. Given this competition for grass and the vast numbers of these rodents in vast towns, the black-tailed prairie cattle was the target of private and federally subsidized poisoning campaigns for well over a century.
Control, especially tax dollar-subsidized control, of black-tailed prairie dogs has long been controversial and contested about on par with subsidized predator control and the national (and, often, state and local) policy on fire supprssion. The subject of black-tailed prairie dogs and inpact on range vegetation, including role in plant and animal succession, was discussed variously throughout Range Types of North America along with the various range types, especially those grassland range types of the Great Plains.
In the short section immediately below, an example of black-tailed prairie dogs and their communal organization on an abandoned alfalfa (Medicago sativa) field in the Central high Plains was presented. This treatment included parts of the old field that were 1) active (currently supporting) and 2) abandoned by black-tailed prairie dogs. Absence of black-tailed prairie dogs from parts of the cropland they had recently occupied provided an example of secondary succesion of a range plant community in the Great Plains of southeastern Wyoming.
Location note: Other examples showing impact of black-tailed prairie dogs on range vegetation in Range Types of North America were included under grassland chapters, entitled Tallgrass Prairie (Interior)- II and True Prairie.
198. Gone to the dogs- An abandoned field of flood-irrigated alfalfa (Medicago sativa) that was invaded (= arrived, colonized, aggregated, and established) by black-tailed prairie dogs that had formed a town across much of this former cropland. Prior to tillage, the climax grassland on this saline range site had been a mid-grass-saltbush savanna with the dominant species being western wheatgrass and with needle-and-thread as the associate herbaceous species while Nuttall's or Gardner's saltbush (Atriplex nuttalli= A. gardernii) was the dominant woody species.
Both of these slides showed the town of black-tailed prairie dogs on this old-field, that was on a Saline Upland range site, at landscape scale. The first slide showed a curent entrance of a prairie dog burrow (right foregroud) along with several others while the second slide presented another part of the old field (now a prairie dog town) with several current burrow entrances.
This range was currently being grazed by cattle and pronghorn (Antilocapra americana) as well as black-tailed prairie dog.
The plant life on this town of black-tailed prairie dog was mostly of the Eurasian weed, field bindweed (Convolvulus arvensis), and, secondly, stickseed or western stickweed (Lappula redowskii= Lappula echinata var. occidentalis= L. occidentalis= L. redowskii var occidentalis) with some scarlet globemallow (Sphaeralcea coccinea) and, locally, Nuttall's or Gardner's saltbush. There were a few plants of blue grama, an increaser for this range site. A description of this Saline Upland range site was given by the Soil Conservation Service (1971, p. 59).
Platte County, Wyoming. Mid-June. FRES No. 38 (Plains Grassland). K- 59 (Wheatgrass-needlegrass). SRM 607 (Wheatgrass-Needlegrass). No biotic communmity unit in Brown et al, (1998, p. 40) adequately fit this natural plant communituy: should have been a Wheatgrass or Wheatgrass-Needlegrass Series such as 142. 14 in Plains Grassland 142.1 of Cold Temperatue Grassland 142. Saline Upland range site- Southern Plains High Plains- Moderate Relief Rangelands Ecoregion 25c (Chapman et al., 2004).
199. Doggone weeds- Population of field bindweed with some western stickseed on a black-tailed prairie dog town established on an old field of irrigated alfalfa. Small mounds of mostly bare soil were around entrances to prairie dog burrows. Most plant cover was that of the Eurasian weed, field bindweed with local patches of the native stickseed or western stickweed. Field bindweed is a naturalized perennial weed whereas western stickweed is an annual or, sometimes, biennial.
This author has observed that field bindweed is one of the most abundant--commonly, the dominant--plant on the typically heavily denuded towns of black-tailed prairie dog. Presence of (dominance by) the exotic yet naturalized field bindweed obviously prompted speculation as to what plant species (if any) would have established, persisted, whatever on the overgrazed range of black-tailed prairie dog towns prior to introduction of field bindweed by the whiteman. For example, would the native western stickseed have been the dominant plant? Would blue grama, an increaser for this range site, have persisted, perhaps as the dominant?
At any rate, this part of the old field that was an actively (currently occupied) by black-tailed prairie dogs was a weed patch, pure and simple. There was essentially no grass cover (even of annual weeds like chetgrass or downy brome) on the populated prairie dog town.
Platte County, Wyoming. Mid-June. FRES No. 38 (Plains Grassland). K- 59 (Wheatgrass-needlegrass). SRM 607 (Wheatgrass-Needlegrass). No biotic community unit in Brown et al, (1998, p. 40) adequately fit this natural plant community: should have been a Wheatgrass or Wheatgrass-Needlegrass Series such as 142. 14 in Plains Grassland 142.1 of Cold Temperatue Grassland 142. Saline Upland range site- Southern Plains High Plains- Moderate Relief Rangelands Ecoregion 25c (Chapman et al., 2004).
200. Dogged survivors- Population of field bindweed growing around the entrance of a black-tailed prairie dog burrow (first slide) and a local stand of Nuttal's or Gardner's saltbush with some cover of field bindweed and western stickweed on a small area of largely bare soil in a prairie dog town (second slide) on part of an abandoned, irrigated alfala field.
Gardner's or Nuttal's saltbush is a climax decreaser for this Saline Upland range site (Soil Conservation Service, 1971, p. 59). The field bindweed and western stickweed are invaders. Plant life on this currently occupied prairie dog town was nothing much beyond a weed patch, except for some small local areas of Gardner's or Nuttal's saltbush (the climax dominant woody species) that were recovering natural vegetation.
Platte County, Wyoming. Mid-June. FRES No. 38 (Plains Grassland). K- 59 (Wheatgrass-needlegrass). SRM 607 (Wheatgrass-Needlegrass). No biotic communmity unit in Brown et al, (1998, p. 40) adequately fit this natural plant communituy: should have been a Wheatgrass or Wheatgrass-Needlegrass Series such as 142. 14 in Plains Grassland 142.1 of Cold Temperatue Grassland 142. Saline Upland range site- Southern Plains High Plains- Moderate Relief Rangelands Ecoregion 25c (Chapman et al., 2004).
201. Dogs gone- Part of an abandoned irrigated alfalfa field that was colonized by black-tailed prairie dogs and, then, after some decades, abandoned by prairie dogs and, ultimately, through secondary plant succession developed back to the climax grassland. The first photograph showed a large part of this old alfalfa field vacated by black-tailed prairie dogs and now a nearly single species-stand (a consociation) of western wheatgrass. The second slide featured the entrance of an old (abandoned) prairie dog burrow that was being revegetated by western wheatgrass, a decreaser and co-dominant grass species for this range site. Almost all grass cover in both of these photographs was western wheatgrass. There were a few plants (relatively little cover) of blue grama, an increaser for this range site, in addition to some plants of field bindweed and western stickweed.
The first of these two slides showed part of the old field still populated by black-tailed prairie dogs (far left background) while the rest was of the range supported no prairie dogs and was "going back" to climax range vegetation. Reasons for abandonment of part of the prairie dog town were unknown. Nor was time since occupancy by prairie dogs known. The rhizomatous western wheatgrass was more likely to cover bare soil faster than the cespitose blue grama. The suthor did not see any needle-and-thread on this revegetating part of the range which was being grazed by cattle and pronghorn.
Platte County, Wyoming. Mid-June. FRES No. 38 (Plains Grassland). K- 59 (Wheatgrass-needlegrass). SRM 607 (Wheatgrass-Needlegrass). No biotic communmity unit in Brown et al, (1998, p. 40) adequately fit this natural plant communituy: should have been a Wheatgrass or Wheatgrass-Needlegrass Series such as 142. 14 in Plains Grassland 142.1 of Cold Temperatue Grassland 142.Saline Upland range site- Southern Plains High Plains- Moderate Relief Rangelands Ecoregion 25c (Chapman et al., 2004).
202. After the dogs: go-back land gone back (more or less)- Moist, saline range habitat that suported a rangeland community made up-- prior to tillage--of western wheatgrass, needle-and-thread, and Nuttal's or Gardner's saltbush and which was converted into an irrigated field of alfalfa that was subsequently abandoned to became a town of black-tailed prairie dog. Finally, prairie dogs in turn abandoned the "go-back land" (old field) which finally, reverted, via secondary succession, back to western wheatgrass.
The first slide was of an entrance to a prairie dog burrow that was being revegetated by the highly rhizomatous western wheatgrass. The second slide was of a larger area of recovering (revegetating) of this midgrass-grassland. The naturally re-established range plant community was a more-or-less restored consociation of western wheatgrass. There was some blue grama, an increaser for this Saline Upland range site (Soil Conservation Service, 1971, p. 59), and local patches of Gardner's or Nuttals saltbush, the climax dominant woody plant.
This was a textbook example of secondary plant succession that culminated in the climax range plant community. In the Clementsian or facilitation model the initial causes of denudation were biotic: first, man (anthropogenetic) and, secondly (or secondarily), rodent herbivory.
Platte County, Wyoming. Mid-June. FRES No. 38 (Plains Grassland). K- 59 (Wheatgrass-needlegrass). SRM 607 (Wheatgrass-Needlegrass). No biotic communmity unit in Brown et al, (1998, p. 40) adequately fit this natural plant communituy: should have been a Wheatgrass or Wheatgrass-Needlegrass Series such as 142. 14 in Plains Grassland 142.1 of Cold Temperatue Grassland 142.Saline Upland range site- Southern Plains High Plains- Moderate Relief Rangelands Ecoregion 25c (Chapman et al., 2004).
203. Poor boy on a poor habitat (a a poor rendering by an Epson printer)- Western stickseed (Lappula redowskii= L. occidentalis) on an abandoned alfalfa (Medicago sativa) field that had become a town of black-tailed prairie dog (Cynomys ludovicianus). Typical of such towns was degradation of the range plant community with weeds being the standard plant life.
Lappula species are in the borage family (Boraginaceae). Most Lappula species such as L. occidentalis= L. redowskii are restricted primarily to highly disturbed (weedy) areas such as seen here. The species featured here is native to Eurasia as well as North America.
The second slide was color-managled by an Epson Perfection 600 scanner. The author attempted to restore the image to color of the first slide, which was scanned to the correct color. He failed inso far as viewers can ascertain. Never buy Epson products.
Platte County, Wyoming. Mid-June; full-flower stage.
204. 'bout droughted-out but a mixture sho' 'nough- A relatively grass species-rich "sample" in two 'photo-plots" of climax mixed prairie in the Central Great Plains. Needle-and-thread, blue grama, and western wheatgrass were about equally dominant on this ungrazed (perhaps deferred) range. Sideoats grama, buffalograss, sand dropseed, red threeawn, hairy grama, and cheatgrass were other species that were varied from infrequent (eg. hairy grama) to abundant at local scale (eg. sand dropseed, buffalograss, sideoats grama) Cheatgrass was limited to local disturbed spots. Forbs were extremely limited with incidental composites comprising most of these. The most common (though infrequent) shrub species were plains pricklypear and soapweed yucca.
The plants on this range were largely dormant in early summer during second year of a moderately severe drought. This combined with recent absence of grazing resulted in these photogenic shots of the potential natural vegetation on a western expanse of Central High Plains.
Pawnee National Grassland, Weld County, Colorado. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13, but this missed more than hit it High Plains- Moderate Relief Plains Ecoregion, 25c (Chapman et al., 2006).
205. Grazing disclimax of mixed prairie- A mixed prairie dominated by needle-and-thread with Indian ricegrass as associate converted into a buffalograss-blue grama short grass (co-dominants) disturbance climax by longtern overgrazing by cattle. The associate grass species was sixweeks fescue, a native annual festucoid species. The conspicuous yellow composite was stiff greenthread (Thelosperma filifolium var intermedium) and the white infloresences were on pale or white evening-primrose (Oenothera albicaluis) an annual.member of Onagraceae. (Both of these forbs were shown below with other species from this area.)
Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 38 (Plains Grassland Ecosystem). Mixture of K-57 (Grama-Needlegrass-Wheatgrass) and K-58 (Grama-Buffalograss). SRM 608 (Wheatgrass-Grama-Needlegrass). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
206. Disturbed carpet- Sward of buffalograss-blue grama disturbance climax that replaced a needle-and-thread-dominated mixed prairie tht was the potential natural plant community (climatic climax). View of sward on the shortgrass disclimax introduced immediately above. In addition to the co-dominants other major species included sixweeks fescue, the associate grass, and stiff green thread and pale evening-primrose, the two most abundant forbs on this range. There were a few closely cropped plants of neeedle-and-thread, but the author could not find any Indian ricegrass (none of sufficient size to be identifiable anyway).
Note: range vegetation presented in this and the preceding photograp were typical or representative samples of the overgrazed range. They were not in a sacrifice area. More on this important point in the immediately following caption.
Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 38 (Plains Grassland Ecosystem). Mixture of K-57 (Grama-Needlegrass-Wheatgrass) and K-58 (Grama-Buffalograss). SRM 608 (Wheatgrass-Grama-Needlegrass). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
207. What was before (or The fence made the difference)- Relict needle-and-thread--dominated mixed prairie (Indian ricegrass was associate species) on the other side of the fence from the buffalograss-blue grama disturbance climax shown in the two immediately preceding slides. Buffalograss, blue grama, and sixweeks fescue were also common and important members of this protected strip of grassland, but the fence separated climax bunchgrass mixed prairie from disclimax shortgrass. Overgrazing (longterm overuse), by cattle in this case, was responsible for this range type conversion.
The two most common forbs in the exclosure were stiff greenthread and pale evening-primrose the same as in the overgrazed pasture. Pale evening-primrose appeared to be about as abundant on one side of the fence as the other, but stiff greenthread was clearly much denser and of greater cover on the overgrazed range.
Specification: there was a ranch road that ran alongside the fence on the overgrazed range (visible in both of the photographs described in this caption). The immediately preceding photographs of this shortgrass disclimax were not taken either in or adjacent to the ranch road, but rather out in representative portions of the overgrazed range. Range vegetation presented in the two above slides was not in the sacrifice area of the ranch road.
Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 38 (Plains Grassland Ecosystem). Mixture of K-57 (Grama-Needlegrass-Wheatgrass) and K-58 (Grama-Buffalograss). SRM 608 (Wheatgrass-Grama-Needlegrass). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
208. Overgrazing by the natives- A town of black-tailed prairie dog (Cynomys ludovicianus) on severely degraded High Plains range on which the climax (potential natural vegetation) was a needle-and-thread--dominated mixed prairie with blue grama, buffalograss, and Indian ricegrass as associates. This was the same range site, Loamy Plains, as that of the cattle-induced shortgrass disclimax and the undisturbed needle-and-thread mixed prairie described immediately above. Along this railroad right-of-way black-tailed prairie dogs had established their town resulting in much bare soil and plant cover primarily of plains pricklypear and with stiff greenthread, pale evening-primrose and/or scarlet globemallow supplying most of the herbaceous cover with relative proportions varying at microscale. All remaining blue grama (of which there was little) had been closely clipped so that the about the only remaining grass cover was that of buffalograss. There was not even much cover of cheatgrass which, along with buffalograss, was relatively abundant immediately below track bed of the railroad.
That needle-and-thread was the potential natural dominant (as on the exclosure--outside of the fence--shown above) was clearly shown by two plants of needle-and-thread in the middle of pricklypear patches where, of course, prairie dogs did not venture.
How "natural"--if natural at all--was a "dog town" on railroad tract exclosures? The answer was unknown to this author, but he hastened to point out that range plant communities along railroad rights-of-way have long been regarded as relict vegetation. Railroad corridors have served as relict areas or reference vegetation for decades. Railroad rights-of-way are about the only sources of native prairie left in much of the Corn-Soybean Belt. Abandoned tracks are now used as hiking trails, bridle paths, and "natural parks".
Anyway, prairie dogs had degraded this mixed prairie vegetation to a much lower seral stage (including, contributing to brush [pricklypear] invasion).
Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 38 (Plains Grassland Ecosystem). Mixture of K-57 (Grama-Needlegrass-Wheatgrass) and K-58 (Grama-Buffalograss). SRM 608 (Wheatgrass-Grama-Needlegrass). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
A smorgasbord of range plant communities- The section immediately below presented vegetation from four range sites (Loamy Plains, Shaley Plains, Clayey Plains, and Sandy Plains) that occurred within approximately a mile and a half radius of each other in northeastern Colorado. These photographic samples gave some indication of the remarkable diversity of grassland and grass-shrub savanna communities that developed in the Central Great (High) Plains. Grasslands are "boring" or "monotonous" only to uninformed, inexperienced, or disinterested traveler.
209. Mixed prairie mosaic- Two acrosss-the-land vistas of climax mixed prairie in the Central High Plains. This grassland had as its apparent potential natural vegetation a vegetational mosaic "put together" as intermixed intermediate-size areas of 1) blue grama-buffalograss shortgrass; 2) needle-and-thread-dominated midgrass; 3) western wheatgrass consociations; and 4) scattered plants of sand dropseed, red threeawn, needleleaf [caric] sedge (Carex duriuscula= C. eleocharis= C. stenophylla ssp. eleocharis), fringed sagebrush, scarlet globemallow, pale evening-primrose, stiff greenthread, wild alfalfa or slender scurfpea (Psoralea tenuifolia), and plains pricklypear, this latter being the sole shrub component of this vegetation. A tallgrass element was lacking from this mixed prairie this grassland being a midgrass-shortgrass prairie which--as was shown above and below--on certain range sites was readily degraded into a grazing shortgrass disturbance climax.
The first of thee two photographs featured an area of buffalograss-blue grama shortgrass turf with considerable cover of plains pricklypear. the second photograph local "spots" of shortgrass and western wheatgrass colonies in foreground with stands of needle-and-thread, sand dropseed, and red threeawn in midground. Most common (and conspicuous at this season) forb was stiff greenthread. Both buffalograss and needle-and-thread were at peak anthesis while western wheatgrass spikes had just emerged from their boots. Blue grama was "a long-way off" from blooming and, in fact, had not in the main elongated its shoots beyond mid-height of adult stature. More precisely, blue grama was not at adult stage in this vernal society. Thus blue grama was under-represented in the vernal aspect and in overall appearance. Conversely, needle-and-thread, a cool-season midgrass, was over-represented in these photographs; however, it would have under-represented while blue grama would have over-represented a month to six weeks later at peak of warm-growing season and estival aspect. Such is the nature of range plant communities that are "natural mixtures" of cool-season and warm-season species each group of which has species that are dominants and associates in their own season.
Time (seasonal progression) of phenological development was a major component or characteristic of mixed prairie vegetation in all of these photographs.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 38 (Plains Grassland Ecosystem). Mixture of K-57 (Grama-Needlegrass-Wheatgrass) and K-58 (Grama-Buffalograss). SRM 608 (Wheatgrass-Grama-Needlegrass) and SRM 611 (Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
210. Integration of midgrasses and shortgrasses- "Photoquadrant" of range vegetation on a midgrass-shortgrass mixed prairie in Central Great (High) Plains. Species ranged from the midgrasses, western wheatgrass and needle-and-thread down to shortgrasses (mostly buffalograss and blue grama) plus needleleaf caric sedge and such forbs as fringed sage, stiff greenthread, pale evening-primrose along with a shrub component in plains pricklypear.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
211. Botanical quilt (or What makes a mixed prairie) - More of the mixed prairie patchwork consisting of both midgrass and shortgrass species. In these two "phototransects" the dominant midgrass (and dominant vernal) species was needle-and-thread with sand dropseed the local associate midgrass. Both of these species were conspicuous in both photographs. The dominant shortgrass at this vernal stage of the annual cycle (ie. vernal aspect) and in this vernal society was buffalograss which was at peak anthesis. Blue grama was the local associate shortgrass though at other local habitats (microsite) blue grama was co-dominant. Blue grama would be predominant over buffalograss in the In the estival aspect and society by which time blue grama would have attained adult growth of shoots. Conspicuous forbs were stiff greenthread (first photograph) and scarlet globemallow (second photograph). There were scattered plants of fringed sage and wild alfalfa or slender scurfpea. Plains pricklypear was so sparse as to be undetectable in these photographs.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
212. Three curtain calls for the botanical cast- Three "photoquadrants" showing the range plant community with representative species of a midgrass-shortgrass mixed prairie in the Central Great (High) Plains at peak standing crop of the vernal society. The first of these three photographs showed the "fenceline-like" edge between a local midgrass community (dominated by needle-and-thread in this example) and a local shortgrass community (co-dominated by buffalograss and blue grama in this example). These local communities could be regarded as herbaceous stands.
The second photograph was of a more composite community where shortgrass and midgrass stands overlapped as a local ecotone (transition zone at local scale). Range plant species in this second "photoquadrant" included blue grama, buffalograss, sand dropseed, red threeawn, western wheatgrass, needleleaf sedge, fringed sage(brush), scarlet globemallow, and plains pricklypear.
The third "photoquadrant" was still yet another local community which in this instance was a midgrass stand of needle-and-thread (primarily) and sand dropseed (secondarily) with plains pricklypear as a ground-level shrub. The pricklypear (along with pale evening-primrose) was in flower.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
213. Co-dominant shortgrasses- Ground-level views of the two dominant shortgrass species, blue grama and buffalograss, on a Loamy Plains range site in the Central Great (High) Plains in late vernal aspect and vernal society. Blue grama was on the left in the first slide and on the right in the second slide and vice versa for buffalograss.
Buffalograss was at its maximum vegetative and floral stages of phenological development (full-growth stage of annual shoot elongation [unless very fortunate amble moisture caused later growth] and peak anthesis) whereas the later-maturing blue grama had made a much lower proportion of its annual shoot growth/development at this point in the current growing season. On the Central Plains Experimental Range Dickinson and Dodd (1976) studied phenological development of major plant species and reported that time of flowing was frequently inconsistent with regards to warm- vs. cool-season species. For example, the warm-season buffalograss bloomed at roughly the same time as the cool-season western wheatgrass. Likewise, time of anthesis in cool-season species, needle-and-thread and bottlebrush squirreltail, could be closer to that of buffalograss than buffalograss was to the other warm-season dominant shortgrass, blue grama (Dickinson and Dodd, 1976, table 2). Unlike most other Bouteloua species blue grama is a long-day plant with regard to flowering (Olmsted, 1943). On the range shown here blue grama more commonly bloomed in late June to July (Dickinson and Dodd, 1976, table 2).
The major differences between these two erogrostoid dominants is in general habit with buffalograss being a sod-forming shortgrass with long stolons while blue grama is largely a bunchgrass (cespitose or tufted) that sometimes forms a relatively large matlike growth from short rhizomes (Hitchcock and Chase, 1951, ps. 540, 545; Gould, 1975, ps. 351; 355, Shaw, 2008, ps. 89, 99). Aboveground growth features of blue grama were reported in a classic paper from the Central Plains Experimental Range (Turner and Klipple, 1952). In this author's experience blue grama more frequently grew in this mat (semi-sodforming) form on this and surrounding ranges of the Central High Plains than on ranges in the Southern High Plains where it consistently grew in the more characteristic cespitose habit. The general rule is that blue grama is a bunchgrass whereas buffalograss is a sod-forming grass, but there is considerable phenotypic plasticity so that blue grama has more of a semi-sodforming shortgrass in the Central and Northern Great Plains, especially under heavier grazing (Wynia, 2007).
In addition--or as a corollary--to general morphology or growth habit of these two shortgrass species there have been several general studies into their general biology or natural history as well as specific characteristics. One of the characteristics of range grasses that was once widely studied involved characterizations of height-weight relations often expressed as height:weight ratios, especially as related to utilization or degree of use (Cook et al., 1962, ps. 114-119). Cook et al. (1962, ps. 115, 118) reproduced two figures showing this relationship in blue grama (Figure 3) and blue grama and buffalograss (Figure 7). With light to moderate grazing there is proportionately greater weight in seed stalks (sexual shoots) of blue grama than in buffalograss, Turner and Klipple (1952) found that contribution of sexual portions of tillers in blue grama varied by a factor of 2.5 (10-25% of aboveground biomass) in different years.
In general growth habit and and time of flowering the co-dominant shortgrasses, both warm-season species, complemented each other and timed their phenological development so as to minimize--to some degree--overlap in time and space thereby reducing interspecific competition.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
214. Expanse of shortgrass- Two landscape-scale scenes of blue grama-buffalograss shortgrass plains range. On the "tight land" of shallower soil, especially of the surface layer (Soil conservation Service, 1982) than that of range sites represented above (Loamy Plains range site) and below (Sandy Plains range site) the two co-dominant shortgrasses, buffalograss and blue grama, comprised a substantially greater proportion (cover, apparent biomass, general abundance) of the range plant community. That difference (proportionately more shortgrass than midgrass species) did not appear to be due wholly to range site. The range introduced here and described in several subsequent photographs appeared to be--at least in part-- a grazing disclimax were long-term heavy grazing had reduced relative cover and herbage of midgrass species and where there was much greater portions of annual forbs.
This conclusion was based not so much on lesser portions of needle-and-thread (a species whose favored habitat is sandier soil) or western wheatgrass that thrives best in lower-lying environments like swales, but in the much greater cover of plains pricklypear and, even more so, on cover and density of annual invaders, most notably woolly or bristle-bract plantain (Plantago patagonica) and common, dense-flower, or prairie pepperweed (Lepidium densiflorum). Woolly plantain is variable in life span ranging from the typical annual through biennial to short-lived perennial (McGregor et al. (1986). Both of these are native species, but they have invariably been recognized as opportunistic species (eg. on waste grounds) and indicators of disturbance are as for instance by McGregor et al. (1986) and Weber (1990). In addition, western wheatgrass, the major midgrass species on this range, had received much greater utilization than the two shortgrass dominants on the range that was being (and, in the past, had been) grazed rather heavily to a fairly uniform stubble height.
One of the most widely cited stocking rate papers ever published was that for blue grama range conducted on the Central Plains Experimental Range (Bement, 1969).
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Shaly Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
215. Shortgrass vegetation and a sample of its turf- Transect-scale scene of blue grama-buffalograss shortgrass plains grassland (first slide) and local or quadrant scale view of the sward of this shortgrass range (second slide) under current moderately heavy (stocking was between moderate and heavy rates). In the second photograph almost all of the standing crop was blue grama and buffalograss. The latter was at peak standing crop and full anthesis whereas blue grama had not commenced elongation of sexual shoots.
Physiogonomy and structure of this semiarid, plains grassland as shown in the first of these two slides and the two immediately preceding slides (especially the second) revealed that this range vegetation could be interpreted as a shrub-shortgrass savanna in which the proportionately high cover and density of plains pricklypear showed this low-growing woody plant to be an associate species. Western wheatgrass was overall the distant third abundant grass on this range. Given the relatively uniform height to which this range herbage had been grazed western wheatgrass, a midgrass species, had been defoliated to a much greater degree of use than those of the two dominant shortgrasses. This was one of the major reasons why this author concluded that this grassland vegetation was--to some extent--a grazing disclimax and not solely the product of this shallow-soil "tightland" range site. Bottlebrush squirreltail was also conspicuous on this range at this time, but it was widely scattered and less abundant than western wheatgrass.
Forbs on this range varied from stiff greenthread, conspicuous in the vernal society, scarlet globemallow, fringed sage, denseflower pepperweed, woolly or bristle-bract plantain, and spreading fleabane (Erigeron divergens). These forb species were presented in the next two two-slide sets.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Shaly Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
216. Patches of retrogression- Two "photoquadrants" of a blue grama-buffalograss-dominate plains grassland (or, perhaps more descriptively, a shortgrass-shrub savanna) on a limely upland that was--in part--a grazing disclimax. In addition to the two shortgrass dominants and plains pricklypear (which resulted in a savanna or savanna-like physiogonomy/structure) there were a number of forbs, both annual and perennial, on this range. Forbs were the "center of attention" in these shots. The first photograph presented fringed sage, scarlet globemallow, and woolly plantain while the second slide showed wooly plantain, scarlet globemallow, and spreading fleabane along with the conspicuous though widely scattered bottlebrush squirreltail. Also in the second photograph (lower right foreground) was a cute specimen of green-flowered hedgehog cactus (Echinocereus viridiflorus).
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Shaly Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
217. Spots of annuals- Local spot grazing in a blue grama-buffalograss shortgrass range in the Central High Plains. These were two grazing-induced microhabitats site Even within a grazing disclimax there can be spot grazing resulting in even more range degradation (retrogression) at this microscale, microsites of severe overgrazing. The first of these two "photoquadrants" featured both denseflower or plains pepperweed and wooly or bristlebract plantain. This latter forb was the "star attraction" of the second "photoquadrant". Shoots of blue grama and buffalograss were also present in both photographs.
These species like several of the others on this shortgrass range were presented and described below. Relatively high density and foliar cover of these two invaders (not to mention plains pricklypear) was one of the major reasons why this range worker concluded that the vegetation existing on this range was partially a gracing disturbance climax and not simply an edaphic climax.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Shaly Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
218. Stockers on shortgrass- Steers on late-spring blue grama-buffalograss upland range at outer edge of a sacrific area around a water tank. The dominant range species were blue grama and buffalograss. Scarlet globemallow and kochia (Kochia scoparia) were the major forbs (in that order). Plains pricklypear was very limited, but there was considerably more cheatgrass than on adjoining ranges, including other shortgrass prairie and savanna, mixed prairie, and needle-and-thread--fourwing saltbush savanna.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Shaly Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
219. Range site variant- Mixed prairie on a soil higher in clay along the bench of a local draw or drainage in the Central Great (High) Plains. Rangeland shown here was Clayey Plains range site in contrast to Loamy Plains, Limy Plains, and Sandy Plains sites presented elsewhere in this section. This was a more mesic habitat than the Loamy Plains and Limey Plains range sites. Dominant species were needle-and-thread on slopes and western wheatgrass on floor of draw. Blue grama and buffalograss were associate species. There was more bottlebrush squirreltail than on the other range sites. Fourwing saltbush (Atriplex canescens) was the dominant shrub that replaced plains pricklypear that was the major woody species on Loamy Plains and Limey Plains range sites. Forb species were most of the same as described--most notably fringed sage, stiff greenthread, and scarlet globemallow--with the additions of Rocky Mountain bee plant or pink cleome (Cleome serrulata) and Astragalus adsurgens var. robustior known variously as tufted, purple, prairie, or standing milkvetch. The annual invaders, dense-flowered pepperweed and woolly or bristle-bract plantain, were very limited and there was no kochia.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 Plains Grassland Ecosystem). K-58 (Grama-Buffalograss). SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Clayey Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
Another study in role of grazing on range plant communities in the Central High Plains-The next two photograph-caption sets showed how long-term grazing by range cattle shifted mixed prairie to shortgrass vegetation in the semiarid zone.
220. Tufted midgrasses to sodforming shortgrasses- A fenceline contrast (first slide) and general view of a stocker range (second slide) on a High Plains mixed grass-fourwing saltbush savanna. Immediately outside this perimeter fence the relict grassland-savanna vegetation was needle-and-thread, Indian ricegrass, and western wheatgrass with lesser cover and biomass of blue grama and buffalograss whereas the range plant community grazed by stockers at moderate to fairly heavy stocking rates was overwhelmingly blue grama and buffalograss. Important specification: this was not a matter that under this degree of use (pasture-wide and ignoring varying utilization rates of different species) midgrasses like needle-and-thread, Indian ricegrass, and western wheatgrass were grazed to a stubble height similar to that of blue grama and buffalograss. No, the three midgrass species were not just utilized to greater proportions; they were much less abundant and, in fact, locally absent from the stocker pasture. These taller bunchgrasses had been reduced in abundance and, in some local areas, grazed out.
Longterm grazing use at whatever the stocking rate(s) had been and currently was had converted this range vegetation from a mixed prairie-savanna of three midgrasses and two shortgrasses to a predominately two-species shortgrass community. Had this photograph been taken a month later sand after current peak standing crop of the three midgrass species and buffalograss and, instead, at peak standing crop of blue grama the relative cover and botanical composition would have been the same as at the time of this photograph. For that matter, the physiogonomy of both grazed and ungrazed portions would have been similar because differences in adult height of blue grama where protected (outside the fence) and that of more closely grazed blue grama on the range would still furnish the same contrast in height, and in mixture of cespitose and sodforming species (outside the fence) and predominately sod-forming habits of shortgrasses (on the grazed range). (Recall from above that at this more northern latitude, and in contrast to the Southern High Plains, blue grama produces more of a matlike growth habit, especially under heavier grazing.) At this time in the annual growth cycle of grasses four of the five major grass species were either at or approaching peak growth and development. There were four phenological stages present: 1) :immediate pre-bloom, western wheatgrass; 2) mid-bloom, Indian ricegrass; 3) peak anthesis, buffalograss; and 4) soft-dough grain stage, needle-and-thread.
Note the small size of closely browsed fourwing saltbush in right foreground of the second slide which was compared to fourwing saltbush plants growing on a more moderately grazed range presented in the next three photographs. This moderately grazed range was directly across a section line road which separated it from the range shown in these two photographs.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass) converted to K-58 (Grama-Buffalograss). SRM 608 (Wheatgrass-Grama-Needlegrass) converted to SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
221. Mixed grass-fourwing saltbush savanna- A mixed prairie grassland composition of blue grama, buffalograss, needle-and-thread, Indian ricegrass, and western wheatgrass with cover and density of fourwing saltbush (along with the nearly always-present plains pricklypear) so as to constitute a midgrass-shortgrass-savanna in the semiarid Central High Plains. The range presented in these three photographs was straight across from--and the same range site as--the more heavily grazed range shown in the two immediately preceding photographs. These two pastures were on opposite sides of a section line road.
The two major shortgrass species, blue grama and buffalograss, were the obvious co-dominants on this as on the heavier grazed range across the road, but these two were much less predominant on this lighter grazed pasture. Said another way, range vegetation seen here did not have proportions of the three major midgrass species (needle-and-thread, Indian ricegrass, and western wheatgrass) that were as great as those in the strip of relict vegetation outside the fence (as shown in the preceding slide set), but proportions (relative cover and biomass) of these three were was much higher than in the more heavily grazed stocker range across the road.
Cover and biomass of the three midgrass species were glaringly greater next to and within interspaces among shrubs, especially the larger fourwing saltbush plants. The main forb was scarlet globemallow.
Finally, students should notice all the plants of fourwing saltbush were much larger on this range with lower degree of use than on the more heavily stocked range on opposite side of the road. (This was very pronounced even with three different camera-to-subject distances.)
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect).FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass) converted to K-58 (Grama-Buffalograss). SRM 608 (Wheatgrass-Grama-Needlegrass) converted to SRM 611(Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
222. Savanna in low sand plains- Landscape-scale panarama of a mixed prairie with fourwing saltbush as dominant shrub and plains pricklypear as associate woody speceis forming a savanna in the Central High Plains. The herbaceous components (or "phase"), which was almost exclusively grass species, was textbook mixed prairie with a shortgrass element (blue grama and buffalograss), midgrass element (needle-and-thread, Indian ricegrass, western wheatgrass, and sand dropseed being the major species), and a tallgrass element represented by prairie sandreed (Calamovilfa longifolia). The grasses of this range community thus consissted or or comprised three layers. Forbs were quite limited and sporadic in distribution, but even these included a short-growing species, scarlet globemallow, and mid-height forbs including stiff greenthread, plains prickly poppy (Argemone polyanthemos), and veined dock (Rumex venosus) so that there were two erratic or interrupted forb layers. The two major shrubs also comprised two layers these being an intermediate-height shrub, fourwing saltbush, and a ground-level shrub, plains pricklypear. There were a few (very few) plants of broom snakeweed (Gutierrezia sarothrae) that grew to heights between those of fourwing saltbush and plains pricklypear. This sums to a total of seven layers of range vegetation (three of grass, two of forb, and two of shrubs), a remarkable stratification for this grassland/savanna (a mixed grass-shrub savannah).
Seasonal societies are very pronounced on this range type (or subtype). Seasonal societies are those detrermined by or as seasonal aspects in which different plant species of a range type (a Clementsian association) "make their most vigorous growth, flower, and fruit at different periods of the growing season" such that there are, for example, prevernal societies, vernal societies, estival societies, and autumnal societies (Clements, 1936; Weaver and Clements, 1938, p. 97). In the Clementsian climax hierarchy a seasonal society of climax vegetation was designated as a sociation (Clements, 1936). Sociations were based on life cycles of major plant species, especially subdominants, the phenological development of which was seen to be determined by temperature more than other factors. In Clements' view sociations were most prominent and best developed in grassland with there usually being three sociations in mixed prairie (Clements, 1936).
On this range type (subtype) of sand plains mixed grass-shrub savanna the dominant grass species, which were the community dominaants, changed fron cool-growing to warm-growing season. The overall dominant cool-season species of this range vegetation was needle-and-thread and the overall dominant warm-season species was prairie sandreed. To be sure there were local dominants such as western wheatgrass in swales and blue grama on upland microsites having soil with less sand, but overall (averaged across the entire plant community) such species were subdominants to associates. Indian ricegrass and sand dropseed were other major--usually associate--grass species. Buffalograss was locally an associate to co-dominant species with western wheatgrass in low-lying areas such as swales. There were occasional plants of broom snakeweed.
This range plant community provided a fine example of the phenomenon of seasonal societies from the perspective of herbaceous dominants. The vernal society was dominated and defined by the cool-season and fsstucoid species, needle-and-thread, whereas the estival (at least later in summer) through autumnal societies were dominated by the warm-season and eragrostoid species, prairie sandreed. Blue grama--another warm-season, eragrostoid grass-- was the associate to subdominant grass with prairie sandreed. Prairie sandreed is a tallgrass (and generally large) species while blue grama is a midgrass. Both of these species are rhizomatous, but rhizomes are longer in prairie sandreed so that it is a superior sand-binder.
This range vegetation was mixed prairie which would place it in the Forest-Range Environmental Study (FRES) unit number 38 (Plains Grasslands) as shown by Garrison et al. (1977), but the closest Kuchler System Equivalent that fit this mixed prairie form, dominance type/subtype, (or whatever vegetational level it is) so as to accomodate needle-and-thread as cool-season dominant and prairie sandreed as warm-season dominant was Nebraska Sand Hills Prairie or K-67 as shown in Garrison et al. (1977). Interpretation of this sand plain, or "flat" ("low") dunes, as a "vegetational island" of the Sandhills was consistent with the description by the Society for Range Management (Shiflet, 1994) of rangeland cover type SRM 603 (Prairie Sandreed-Needlegrass) which included the type in northeastern Colorado and southeastern Wyoming as well as the Nebraska Sandhills. Garrison et al (1977) plaaced Kuchler Equivalent 67 under FRES No. 39 (Prairie Grassland Ecossytem) which explained the slight discrepancy below.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 39 (Prairie Grassland Ecosystem). Variant or island of K-67 (Nebraska Sand Hills Prairie). SRM 603 (Prairie Sandreed-Needlegrass). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Sandy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
223. Principal players on a sand plains savanna- Needle-and-thread, the general or overall cool-season dominant of a mixed prairie savannah, at peak standing crop and in soft-dough grain stage of development with fourwing saltbush, the major shrub species, in the Mixed Prairie Region of the Central High Plains. Prairie sandreed, the warm-season dominant of this range vegetation was still in early spring growth as was blue grama. Indian ricegrass was a local associate on habitats of deeper sands like that shown here.
A few younger (smaller) plants of broom snakeweed were in left foreground.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 39 (Prairie Grassland Ecosystem). Variant or island of K-67 (Nebraska Sand Hills Prairie). SRM 603 (Prairie Sandreed-Needlegrass). Brown et al. (1998, p. 40) descraiption: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Sandy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
224. Close-knit players- Needle-and-thread, cool-season dominant, and Indian ricegrass, associate species, with fourwing saltbush and plains pricklypear (first slide) and needle-and-thread and fourwing saltbush "joined at the hip" (second slide) as dominant herbaceous and woody species, respectively, in the vernal society of a mixed grass-shrub savana on a sand plains environment in the Central High Plains.
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 39 (Prairie Grassland Ecosystem). Variant or island of K-67 (Nebraska Sand Hills Prairie). SRM 603 (Prairie Sandreed-Needlegrass). Brown et al. (1998, p. 40) descraiption: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Sandy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
225. Stockers on a sand swale- A swale or wide, shallow drainage in a sand plains mixed grass-shrub savanna in the Central High Plains being grazed by long-yearling steers. The dominant range plant in the swale was western wheatgrass with buffalograss a local associate species. Rangeland along the swale (from slopes outward) was dominated by needle-and-thread in this spring aspect/spring society with fourwing saltbush the local associate to co-dominant species. Prairie sandreed (still at early phenological development at this time) was the herbaceous, warm-season dominant. Blue grama, Indian ricegrass, and sand dropseed were other important grasses. The most plentiful--though uncommon--forb was fringed sage that was conspicuous in the bed of the swale. There were also local patches with colonies of veined dock (Rumex venosus) in disturbed microsites such as local wash spots in the drainage (swale).
Central Plains Experimental Range (Agricultural Research Service), Weld County, Colorado. Mid-June (late vernal aspect). FRES No. 39 (Prairie Grassland Ecosystem). Variant or island of K-67 (Nebraska Sand Hills Prairie). SRM 603 (Prairie Sandreed-Needlegrass). Brown et al. (1998, p. 40) descraiption: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Sandy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
226. Dogged out- Former mixed prairie of blue grama, buffalograss, western wheatgrass, and needle-and-thread that had been overgrazed (primarily by black-tailed prairie dogs though with "assistance" from beef cattle) to a range plant community of little barley (Hordeum pussilum), six weeks fescue (Festuca octoflora), buffalograss, red threeawn (Aristida longiseta), plains pricklypear, and cheatgrass or downy brome. There were some plants of wild alfalfa (Psoralea tenufiolia) and very limited cover of blue grama. This range had been degraded to Poor range condition class through overgrazing.
Weld County, Colorado. Mid-June, vernal aspect. FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass) converted to "total degradation". SRM 608 (Wheatgrass-Grama-Needlegrass). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. Loamy Plains range site. High Plains-Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
227. The dominant- Blue grama (Bouteloua gracilis) was co-dominant (with buffalograss) on a shortgrass plains range that was to some extent a grazing disclimax. Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado.Mid-June (late spring), early bloom stage.
228. Stand of shallow-rooted ones- Local population of small and heavily grazed plants of sixweeks fescue (Festuca octoflora), a native, cool-season annual grass. This was patch of a single species was microsite within a cattle-wildlife range dominated by blue grama, buffalograss, and sideoats grama. It was currently being grazed by cows and calves, pronghorn (Antilocapra americana), black-tailed jackrabbit (Lepus californicus), and mule deer (Odocoileus hemionus). The two plants lying flat on the soil surface had been pulled up by cattle. This phenomenon was a combined function of the shallow-rooted feature of the annual grass and the pulling force of feeding by range animals whose main prehensile organ is their tongues.
Overall range condition class of this pasture was high Good to low Excellent.
Pawnee National Grassland, Weld County, Colorado. Late June (early summer); death phenological stage (completion of annual life cycle).
229. Three examples of a little one- Three plants of the relatively small (though common) annual grass, sixweeks fescue (Festuca octoflora) on Central Great Plains mixed prairie of mid-grasses such as sideoats grama and western wheatgrass and shortgrass species, especially buffalograss and blue grama.
The first two plants (top to bottom) were senescing while the third plant had already died (completed the life cycle of an annual species). None of these three plants had received any grazing on this cattle range that also supported populations of mule deer, pronghorn, and black-tailed jackrabbits. The immediately preceding slide-caption set showed that cattle readily will take sixweeks fescue even on high successional status mixed prairie.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado. Mid-June (late spring); senescing to dead phenological stages.
230. Not a purple cow, but purple milkvetch- Purple, prairie, tufted, rattle, or standing milkvetch (Astragalus adsurgens var. robustior), and there are probably several other common names out there just waiting to be milked. There are a "gazillion" Astragalus species on the Western Range. Weber (1990, ps 183-188) listed almost 40 species of Astragalus for the eastern slope of Colorado. This is one of the more common species. These plants were growing in a moist draw on a range that had received light livestock grazing, at least in the current growing season.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado.Mid-June (late spring), full-bloom stage.
231. Purple standing on the short prairie- Inflorescence of purple, prairie, standing rattle, or tufted milkvetch. Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado.Mid-June (late spring), early bloom stage.
232. Plain pepper- Common or prairie pepperweed (Lepidium densifolium) on grazing disclimax shortgrass plains range. This was one of the major forbs on the buffalograss-blue grama range described above. It was frequently the local dominant plant. This annual crucifer is one of the classic indicator species of overgrazing or other disturbances, and on a diverse array of range plant communities.
The short, rounded fruits of this species are of the fruit type known as silicles, cruicifer fruits that are relative short in comparison to their length.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado. Mid-June, early fruit-ripening stage of phenology.
233. Plain plantain- Wooly plantain or wooly Indianwheat (Plantago patagonica) was the other major forb on the buffalograss-blue grama grazing disclimax range described above. This annual, like about all other Plantago species, is a weed, both economically and ecologically. Wooly plantain is an invader and an obvious indicator species of disturbance such as overgrazing. Cause of the denuded microsite seen here was known but to God, but it was a textbook example of this native, pioneer range plant successfully invading "new land" and, thereby, setting the stage for revegetation of the denuded spot via secondary plant succession.
Fortunately, most of this range that had obviously been subjected to overuse for "quite a spell", was not to the state of degradation (= stage of retrogression) as was this microhabitat. Still, and even without complete baring of the soil surface, there was more than enough grazing abuse for this unpalatable range forb to have a nice home along with its "extended family" (ie. a healthy population of P. patagonica). Wooly plantain was also successful in establishing itself over much of this range where existing vegetation was less drastically impacted. Wooly plantain is not restricted to overgrazed ranges. Abundant populations can also be found, when growing conditions have been favorable, on properly grazed ranges. However, wooly plantain is generally unpalatable and eaten by livestock mostly when little else is available. It is a classic invader in the model of Clements (1920) and Dykersterhuis (1949). Stubbendieck et al. (1992. p. 387) described wolly Indianwheat as being good forage for sheep for which it can be "a major forage species on lambing rnges".
This warm-season forb also "established" itself in the range plant literature earning spots in the old standby Range Plant Handbook (Forest Service, 1937, W150), the popular Pasture and Range Plants (Phillips Petroleum Company, 1963, 2003), Notes on Western Range Forbs (Hermann, 1966, p. 271), and by earning a place on the 200 species Master Plant List for the International Range Plant Identification Contest, North American Range Plants (Stubbendieck et al., 1992, ps. 386-387). Perhaps the main attribute for making such a "big hit" was the extremely wide distribution of this species that extends from some the Canadian Maritime provinces to British Columbia and south deep into the Republic of Mexico (see above references).
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado. Mid-June, peak-bloom stage of phenology.
234. Wooly range wheat- Shoots (first slide) and inflorescences (second slide) of wooly Indianwheat or wooly plantain on a shortgrass (buffalograss-blue grama) distirbance climax. range. This was on an upland and "tightland" (versus sandy) form of mixed prairie under extreme semiridity. The common name Indianwheat was supposedly derived from the Indian practice of gathering the ripe seeds as a food source. But then again, was there anything the Indians did not eat over much of their hardscramble habitat? Most livetock and wildlife do not eat it.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado. Mid-June, peak-bloom stage of phenology.
Location Note: other coverage of Plantago patagonica was provided with coverage of tall fescue (Festuca arundinacea) in the chapter entitled, Introduced Forages- Grasses. That chapter was placed under the Grasslands group within Range Types of North America.
235. Green thread and yellow spools- Stand of stiff greenthread (Thelosperma filifolium var intermedium) on a heavily grazed mixed prairie that was closer to a grazing disclimax shortgrass plains range. Central High Plains. Weld County, Colorado. Mid June (late spring), peak-bloom stage of phenology.
236. Flowering shoots of stiff greenthread- Heads on shoots of stiff greenthread growing on a heavily utilized range in the Central High Plains.
237. Spreading across shortgrass- Spreading fleabane (Erigeron divergens) on a grazing disclimax form of shortgrass plains. There are various Erigeron species native to the Great Plains and closely adjacent regions like the Colorado Piedmont and San Luis Valley. Two more of these are Engelmann's fleabane (Erigeron engelmannii) and tufted fleabane (Erigeron caespitosus), the latter of these was shown and described below while the former was included with species of the black greasewood scrub treated in the Miscellaneous Shrubland chapter of Range Types. All of these are occasional rather than dominant or even associate composite forbs. They do provide a good example of speciation.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado.Mid-June (late spring).
238. Something besides white or yellow- "Almost all" composites have heads with white or yellow petals so the purple corollas of tansey aster or tanseyleaf aster (Aster tanacetifolius= Machaeranthera tanacetifolia) afforded a proverbial welcome departure here on the grazing disclimax of a shortgrass plains range. OK, its weedy little beggar, but what the heck. A little variety with the buffalograss can't hurt too much. Besides these floral folk were holding their own smack dab in the middle of a black-tailed prairie dog (Cynomys ludovicianus) town. That's worthy of picture in itself.
Weld County, Colorado. Mid-June (late spring).
239. Green with envy- Green-flowered hedgehog cactus (Echinocereus viridiflorus) in its sexual prime. This cute little specimen was growing on the more-or-less manmade (disclimax) shortgrass plains of the Central High Plains described above. Most of the grass surrounding this cactus was blue grama with buffalograss second.
Echinocereus species are in Cactaceae subfamily Ceroideae.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado. Mid-June, peak-bloom phenological stage.
240. Rocky Mountain bee plant or pink cleome (Cleome serrulata)- This annual forb of the caper family (Capparaceae) was growing in a moist draw on the deeper soil of an upland range in the Central High Plains. Its neighbors included the milkvetch known by such adjectives as purple, prairie, tufted, rattle, or standing (shown above) as well as wild alfalfa or scurfpea, blue grama, buffalograss, needle-and-thread, red threeawn, and sand dropseed.
In addition to the many colorful flowers borne in racemes, the trifoliate leaves (three leaflets) make this range forb readily identifiable and prominent on the Great Plains landscape.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado. Mid-June, peak-bloom phenological stage.
241. One that can be stuck in anywhere- Local stand of scarlet globemallow (Sphaeralcea coccinea). One of the most common and widely distributed forb on mixed prairie through shortgrass plains grasslands is this member of the Malvaceae, mallow family. This bunch was growing on a green needlegrass-dominated mixed prairie range featured below, but millions just like it grew over the rest of western mixed prairie ranges (ie. this shot could have been just about anyplace in the Great Plains). Hermann (1966, ps. 179-180) reported that scarlet globemallow has a biological range extending from Alberta to Texas and into the Central Lowlands province as far east as Iowa with palatability varying from tremendously from poor (or even none) to good. Oddly, this species was not included in either the Range Plant Handbook (Forest Service, 1937) nor Pasture & Range Plants (Philllips Petroleum Company, 1963, 2003). Yet, there are countless acres of Great Plains grassland on which scarlet globemallow is the--as in the singlularly most abundant--range forb.
Scarlet globemallow is on the Master Plant List (of 200 species) of the International Range Plant Identification Contest sponsored by the Society for Range Management and described in North American Range Plants (Stubbendieck et al., 1992).
Washington County, Colorado. Mid-June (late spring), full-bloom stage.
242. Scarlet globemallow- Apices of sexual shoots (first photograph; Washington County,Colorado) and close-up of flower (second photograph; Costillo County, Colorado) of one of the most common forbs of the mixed and shortgrass country.
243. Pale face on overgrazed mixed prairie- Pale or white evening-primrose (Oenothera albicaluis) growing beside scarlet globemallow (most leaves seen here). Both of these range forbs were growing on a black-tailed prairie dog town the ground of which had very few other species. Apparently prairie dogs do not care to eat (or even clip off) plants of these two species. O. albicaluiss is one of the more common evening-primroses on the Central Great Plains.
Weld County, Colorado. Mid-June, peak-bloom phenological stage.
244. Pale faces up close- Detailed views of inflorescneces of pale or white evening-primrose on a black-tailed prairie dog town in the Central Great Plains. Weld County, Colorado. Mid-June, peak-bloom phenological stage.
245. Veined on the plains- Local colony of veined dock (Rumex venosus) on a "sandyland" (sand form) mixed prairie dominated by neede-and-thread. This was a modified or "semi-sandhills" subtype, a transition grassland intermediate between the classic sandhills and "hardland" (a less mesic range environment). Veined dock is one of the more chracteristic (and, certainly, conspicuous) range forbs on this variant of mixed prairie, especially on disturbed areas like degraded.range.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado. Mid-June, peak-bloom stage of phenology.
246. Prominently winged-Apices of sexual shoots of veined dock growing on a local denuded microsite on a variant of "sandyland" needle-and-thread dominated mixed prairie. The showy floral organs are gynoecia (singular, gynoecium) with fourunited carpels each of which is unilocular with one ovule. Mature fruit is a lenticular (three-sided) achene (Smith, 1977, p. 112). The uniquely pronounced winglike carpels are basis of another common name for this Rumex venosus, wild bignolia.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado. Mid-June, peak-bloom stage of phenology.
247. Not all are invasives- Nice specimen of wavyleaf thistle (Cirsium undulatum) growing on a climax needle-and-thread and western wheatgrass true prairie that developed on a high clay-content soil in the Colorado Sandhills. This native composite grew on a steer (stocker) range that was in Excellent range condition class (ie. at the climax state of the range plant community for this range site).
The lesson taught to Range Management students in this example was that simply because a range plant is a member of a genus, tribe, etc. that is notorious for weeds is no guarantee that such species (or all members of that taxon) are weeds. Cirsium is a genus of dreadful weeds including Canada thistle (C. arvense) and the introduced (and now naturalized) Eurasian species, common or bull thistle (C. vulgare). Both of these species along with wavyleaf thistle were described in the reference, Weeds of the West (Whitson et al., 1992). Whereas alien, undesirable (for whatever reasons) species can regarded and treated as weed species, native species that are weeds in certain situations cannot be interpreted as a weeds in most instances.
That is the situation with wavyleaf thistle. Under certain ecological, economical, cultural, etc. environments the native, perennial wavyleaf thistle is a desirable range plant. Wavyleaf thistle is a member of the climax range plant community, but at relatively low cover, density, and proportion of the potential natural community (climax). On some range sites wavyleaf thistle is an increser whereras on other range sites it is an invader. This is in contrast to, say, common thistle, a Eurasian species that is always an invader. Finally it should be noted that even the most invasive of noxious weeds has some value. Both bees and horses love to feed on thistle flowers.
Washington County, Colorado. Mid-June; peak bloom phenological stage.
248. Purty lookin' native- Top-down view of capitula (heads) and leaves (upper slide) and sive-view of a capitulum (second or lower slide) of wavyleaf thistle, a native perennial of the thistle tribe (Cynareae). This Cirsium species is quite palatable to most livestock species.It is widely distributed throughout the greater Great Plains and eastward to parts of the Central Lowlands province.
The example seen here was growing on a mixed prairie stocker range that was in Excellent range condition class. The major species on this range were needle-and-thread and western wheatgrass with sand sagebrush present at low cover. This range was not a sand sagebrush-grass savanna).
Washington County, Colorado. Mid-June; peak-bloom phenological stage.
249. Grassland mosaic- A mixed prairie in a three-way dominance of blue grama, buffalograss, and western wheatgrass on the Central High Plains. In the first view (which was shown in the first two photographs) there was a mixture of blue grama, needle-and-thread, and buffalograss in the foreground and with "strips" of western wheatgrass in drainage areas or shallow depressions in the background that were interspersed in with populations of blue grama and buffalograss. (The first landscape shot was shown the same slide scanned twice--scanned once in each of two separate "batches" of slides--by an Epson 700 Perfection scanner. The first of these scans reproduced more accurately the color of the herbage.) In the third slide the immediate foreground was a nearly single-species stand of blue grama with a zone of western wheatgrass (with its characteristic glaucous blue-green color) behind and then more blue grama in distant background with buffaolgrass interspersed among the blue grama populations. Growing in with the bunchgrass-forming blue grama were plants of the native annual grasses, little barley and six-weeks fescue, both species of which are cool-season, festucoid grasses.
In this range plant community of largely segregated populations of three "tri-dominants" the grassland vegetation appeared mostly as a patchwork or mosaic rather than as a homogenous "three-way mixture" such as that in foreground of first slide. This mosaic of "pure" patches of first one grass species and then another was due to the predominant mode of asexual reproduction in which a species was present primarily as a clonal colony of one to a few genotypes. This was more the case for the rhizomatous, sod-forming western wheatgrass and buffalograss than the cespitose, tillers-only blue grama.
This public range was a cattle (cow/calf pairs) allotment, but there haed not been any grazing during the current growing season due to local oil development in this mixed prairie range.
Pawnee National Grassland, Weld County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands). K-61 (Wheatgrass-Grama-Buffalograss). SRM was mixture of 610 (Wheatgrass) and 611 (Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains-Flat to Rolling Plains Ecoregion 25d (Chapman et al., 2006).
250. Mosaic of mixed prairie- The"lay of the land" of the Central Great Plains carpeted with midgrass species--especially western wheatgrass with some needle-and-thread, sideoats grama, and sand dropseed--and shortgrass species--mostly blue grama and buffalograss with some hairy grama--along with sixweeks fescue and plains pricklypear (yellow flowers in foreground of the first slide). Cover of plains pricklypear was of such proportion that a case could be made that this was, strictly speaking, a savanna.
At this season the warn-season midgrasses had not attained their adult height so this range still appeared to be "shortgrass country", but it was textbook mxed prairie, and in Good to Excellent range condition class.
The flat, starkness of the terrain combined with the mingled patches of midgrass and shortgrass prairie made for a sight fit only for a plainsman, a grassland of such physiogonomy, structure, and composition that only a grasslander or rangeman could love (but love it we do). God's own grass country.
Pawnee National Grassland, Weld County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands). K-61 (Wheatgrass-Grama-Buffalograss). SRM was mixture of 610 (Wheatgrass) and 611 (Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains-Flat to Rolling Plains Ecoregion 25d (Chapman et al., 2006).
251. All assembled- Two composite shots of classic mixed prairie on the Central Great Plains with the nearly complete complement of all the native grasses "present and accounted for". Between these two large "photoquadrants", almost all of the cool-season and warm-season and the midgrass and shortgrass species of this grassland were represented. Western wheatgrass, needle-and-thread, and sideoats grama were the major midgrasses whereas buffalograss, blue grama, hairy grama were the most abundant shortgrasses. Little barley (Hordeum pussilum) and sixweeks fescue (both are native, cool-season annual grass species) sdtood among their perennial brethern while the perennial grasslike plant, threadleaf caric sedge was well-represented. There were also some plants (though of minor cover) of plains priclypear such that there was a woody (shrub) component as well.
The large yellow-green patch at left and center in the second slide was buffalograss which was at peak bloom; western wheatgrass and needle-and-thread stood to the right of the turf-forming buffalograss.
This public range was a cattle allotment (Pawnee National Grassland), but it was closed to livestock grazing at this time to allow for oil development. This range was well-stocked by pronghorn, the most graceful of the Great Plains herbivors. The ungrazed sward of this mixed prairie made for good photographs that showed structure as well as species composition of this extraordinary grassland.
And we all own it in common!
Pawnee National Grassland, Weld County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands). K-61 (Wheatgrass-Grama-Buffalograss). SRM was mixture of 610 (Wheatgrass) and 611 (Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains-Flat to Rolling Plains Ecoregion 25d (Chapman et al., 2006).
252. Mostly western wheatgrass- Consociation of western wheatgrass in the Central Great (High) Plains on a clayey soil. The glaucous metalic-toned majority of herbage was western wheatgrass while the more typical green in small patches was buffalograss or buffalograss and blue grama mixed. In the context of Lancscape Ecology--though at microscale--this sward was a western wheatgrass matrix with local patches of bufalograss-blue grama. Said another way, this was a mosaic of primarily western wheatgrass-dominated midgrass prairie with local smaller bits of buffalograss-blue grama shortgrass prairie.
This public allotment on Pawnee National Grassland had not been grazed during the current growing/grazing season because there was oil field development on this range. A little deferment never hurt a range.
Pawnee National Grassland, Weld County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands). K-61 (Wheatgrass-Grama-Buffalograss). SRM 610 (Wheatgrass). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13 was the closest unit published, but there should have been (should be) be a Wheatgrass Series such as, say, 142.14. High Plains-Flat to Rolling Plains Ecoregion 25d (Chapman et al., 2006).
253. Another of Nature's single-species stands- Another consociation of western wheatgrass on a finer textured (higher clay content) soil in the Central Great Plains. The sward of this grassland was, for all practical purposes, a "pure" (100 percent cover) stand of western wheatgrass, but strangely enough the only other grass species to speak of was sand dropseed, a species that, as indicated by its common name, does best on sandy soils. Obviously there was adequate sand in with the primarily clay soil (soil texture class was not known) to support sand dropseed. Mother Nature is full of surprises.
The cover on the soil surface in among the tall shoots of western wheatgrass was also essentially 100 percent western wheatgrass, only the partially decayed shoots grown in the previous year. In this local area there had been inadequate precipitation to decompose all of last year's herbage. Also, this range had not been grazed yet in the current growing season. This management fact explained the extremely tall western wheatgrass shoots that had received little if any defoliation. Pronghorn and black-tailedjack-rabbits (Lepus californicus) were free-ranging throughout this area.
Pawnee National Grassland, Weld County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands). K-61 (Wheatgrass-Grama-Buffalograss). SRM 610 (Wheatgrass). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13 was the closest unit published, but there should have been (should be) be a Wheatgrass Series such as, say, 142.14. High Plains-Flat to Rolling Plains Ecoregion 25d (Chapman et al., 2006).
254. Blended grassland- Two "photoplot" views of mixed prairie on the Central Great Plains. Range vegetation in the first slide was an unusually open sward of western wheatgrass with mature shoots of buffalograss and young (baby) shoots of blue grama below in the midgrass species so as to form a two-layered grassland. The second slide showed the "mix" of the first slide at closer camera range and adorned by the rose-colored flower form of plains pricklypear. There was a sproadic cover of this low-growing shrub resulting in a woody component in this grassland. In local areas cover of pains pricklypear was proportionately great enough that the range plant community was more of a savanna than a grassland (a savanna form of mixed prairie).
This public range was a cattle allotment, but livestock had not been allowed this year in order to facilitate oil development on land administered by the USDA Forest Service. National Grasslands are part of the National Forest System so Multiple Use is a central mission in their mamagement: "Lands of Many Uses".
Pawnee National Grassland, Weld County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands). K-61 (Wheatgrass-Grama-Buffalograss). SRM was mixture of 610 (Wheatgrass) and 611 (Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains-Flat to Rolling Plains Ecoregion 25d (Chapman et al., 2006).
255. No different than the buffalo- Cow/calf parirs on a degraded mixed prairie range in the Central Great Plains. This grassland was a grazing disturbance climax (zootic disclimax). The climax range plant community or potential natural vegetation was a mixed prairie of western wheatgrass, blue grama, and buffalograss as three-way co-dominance (these were the "tri-dominants") with needle-and-thread, sideoats grama, hairy grama, and, in local more sandy soil, sand dropseed. Threadleaf caric sedge was also a local major species of the climax vegetation. The present range vegetation was primarily a blue grama-buffalograss (co-dominants) shortgrass plains grassland with the midgrass species of western wheatgrass, needle-and-thread, and sideoats grama greatly reduced in cover due to overgrazing. Threadleaf caric sedge had suffered less reduction in foliar cover.
The main departure from climax was a great increase in cover and density of plains pricklypear. Even though the three midgrass species had been reduced through longterm overuse (overgrazing) there was still an adequate number of plants of these species that these midgrasses would recover (and rather quickly given a few years of favorable soil moisture conditions) so that range recovery and restoration of the climax grassland would be likely. Specifically, there was still appreciable basal cover of the midgrasses, especially the rhizomatous, sod-forming western wheatgrass which was the one midgrass of the three tri-dominant species of this grassland community. Recovery of the cespitose needle-and thread would take longer. Sideoats grama was minor compared to the two cool-season midgrass species.
Reduction of plains pricklypear in relation to herbacesou (grass) cover was more problematic. Fire would do the trick quickly and effectively (as would herbicidal treatment which woul likely not be cost-effective). Increase in grass cover (greater relative or percentage composition of grass relative to pricklypear) due to competition would take longer, but was more than likely the actual situation.
Even with lighter utilization (degree of use) in the current growing season cover of midgrasses would have been substantially greater such that plant species composition (relative percentage or proportion of the plant species) of this range would vary depending upon whether basal or foliar cover (not to mention biomass or density measurements) was the criterion. A considerable part of the physiogonomy of this grazing disclimax was due to degree of use and not necessarily to cover per se.
Among pioneer grassland ecologists much of the shortgrass prairie, especially the buffalograss-blue grama type was a grazing disturbance. In fact, Weaver and Clements (1938, p. 524) designated this as the Short-grass Disclimax. "...[D]ominnce of the short grasses is a result of overgrazing" such that the shortgrass country "...is a modified form of the mixed prairie" (Weaver and Clements, 1928, ps. 524-525). Near extermination of the North American buffal (Bison bison) resulted in a recovery of midgrasses and return of the mixed prairie (Weaver and Clements, 1938, ps. 469-470).
The "whiteman's buffalo" have on many ranges, such as the one presented here, preserved this "family tradition". Beef cattle may not be the exace ecological equivalent of the native buffalo, but they obviously are of little or no difference when it comes to their influence on grasslands of the mixed prairie.
Pawnee National Grassland, Weld County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands). K-58 (Grama-Buffalograss). SRM 611 (Blue Grama-Buffalo Grass). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13 or, in areas, Grama "Short-Grasss" series 142.12. High Plains-Flat to Rolling Plains Ecoregion 25d (Chapman et al., 2006).
256. A rough blend- Mixed prairie in the Central Great Plains with a combination of short- and mid-grasses and cool- and warm-season grass species at the turn of the seasons. Needle-and-thread and western wheatgrass, the two dominant midgrasses, and buffalograss and bluegrama, the two dominant or co-dominat shortgrassess along with wild alfalfa or gray scurfpea (Psoralea tenuifolia) as the number one forb made up most of the herbage (standing crop) seen here. Associate herbaceous species (sometimes local dominants) included sideoats grama, hairy grama, sixweeks fescue, and sand dropseed. Plains pricklypear comprised the woody component, but this low-growing shrub was much too widely scattered for this range vegettion to qualify as a savanna. Soapweed yucca was absent from the range plant community shown here.
Much of the dead (amber-colored) herbage were the now-dormant shoots of the co-dominant cool-season midgrass species. Buffalograss was at its peak of development (anthesis phenological stage) and peak standing crop whereas the three grama grass species had just begun to send forth green leaves (three to four inch stage). Sand dropseed herbage was a combination of last year's dead and this year's beginning-growth shoots. Wild alfalfa was in pre- to very early bloom phenological stage.
This combination of warm- and cool-season species, short- and mid-grasses, grasses and forbs, and herbaceous and woody plants made for a neat, but a rough-looking blend of range feed.
Pawnee National Grassland, Weld County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands). K-61 (Wheatgrass-Grama-Buffalograss). SRM was mixture of 610 (Wheatgrass) and 611 (Blue Grama-Buffalograss). Brown et al. (1998, p. 40) description: Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains-Flat to Rolling Plains Ecoregion 25d (Chapman et al., 2006).
257. Major herbivore was an invertebrate- Mound of a colony of western harvester ant (Pogonomyrmex occidentalis) on mixed prairie in the Central Great Plains. Range Management Students should not forget that many species of herbivores are invertebrates.
Agricultural Research Service Central Plains Experimental Range, Weld County, Colorado.
258. Mid- and shortgrass, but no tallgrass- Three landscape views of a botanically rich mixed prairie of midgrass and shortgrass species serving as a cattle (cow/calf) range in the outer edge of the Laramie Basin in the Central Great Plains. Almost all herbage on this mixed prairie range, that was at the climax state, was that of native grasses including Canby's bluegrass (Poa canbyii), Junegrass, needle-and-thread, blue grama, and western wheatgrass. No buffalograss, sideoats grama, hairy grama, or green needlegrass was found. There were no tallgrass species present; nor was buffalograss encountered. Range forbs were limited to three speices: 1) hoary fleabane (Erigeron canus), 2) foothill arnica (Arnica fulgens), and 3) white beard-tongue (Penstemon albidus). These three species were poorly represented by widely scattered individuals. Likewise, woody species were limited to a few plants of plains pricklypear.
The various grass species were local dominants that grew in single-species patches (small-scale consociations). For example, one such local population of Junegrass was visible in the foreground of the second slide whereas most of the herbage in the third slide was a large, expansive population of Canby's bluegrass (the amber or tan-colored strip that occupied most of the photograph). The amber color was due to dead shoots of Canby's bluegrass, plants of which had entered the dormancy stage of the annual growth cycle of this cool-season species. A confusing situation existed in regard to some populations of Canby's bluegrass where other grass species grew among shoots or cespitose plants of the locally dominant Canby's bluegrass. This was the case for Canby's bluegrass seen in slide three where blue grama and Junegrass grew among the large, tufted, and now-dormant plants of Canby's bluegrass.
Grassland vegetation in the first slide was a complex "blend" of all the major grasses, but western wheatgrass and Junegrass predominated.
This country was in a comparatively dry spring though not a serious drought.
Temperment of the cattle on this range were an exception to the general rule that high-successional range is grazed by docile cattle. Not so on this outfit: climax mixed prairie vegetation and cattle that were black, high-headed, wilder than pronghorn companions, and that high-tailed it over the low hills before this experienced photographer could unsling his Nikon.
Laramie County, Wyoming. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslaneds Ecosystem). K- 57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Variant form of Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed Short-Grass Series 142.13 (Brown et al., 1998, p. 40). High Plains- Moderate Relief Rangeland ecoregion 25c (Chapman et al., 2004).
259. Species-rich sward of mixed prairie- "Looking down" view of the range vegetation of a midgrass-shortgrass mixed prairie in the Laramie Basin Central Great Plains. Dominant, associate, and important minor species in this "photoquadrant" of the sward included Canby's bluegrass, Junegrass, blue grama, needle-and-thread, and western wheatgrass. Buffalograss was conspicuous by its absence as were downy brome (cheatgrass) and Japanese brome, two naturalized Eurasian annual grasses that are found in this Wyoming county (Great Plains Flora Association, 1977).
Though white penstemon, foothill arnica and hoary fleabane were growing on this cattle (cow/calf) range these forbs were generally scarse and were characteristically absent from this "photoplot".
Laramie County, Wyoming. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslaneds Ecosystem). K- 57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Variant form of Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed Short-Grass Series 142.13 (Brown et al., 1998, p. 40). High Plains- Moderate Relief Rangeland ecoregion 25c (Chapman et al., 2004).
260. No fleas on the Central Plains- Hoary fleabane (Erigeron canus) on a mixed prairie in the Central Great (High) Plains, specifically the Laramie Plains portion. Hoary fleabane is a perennial forb. There are many Erigeron species on North American grasslands. Great Plains Flora Association (1986, ps. 926-933) described 23 species of Erigeron for most of the Great Plains and much of the Central Lowlands provinces. In the authors experience, the Erigeron species are not very palatable, especially not to cattle which was the sole livestock species grazing the range that served as habitat for example presented here. Erigeron species are members of the Astereae, aster tribe.
Laramie County, Wyoming. Mid-June; and no question about full-bloom phenological state.
261. Another forbaceous member of the same range- This short-statured beauty of foothill arnica (Arnica fulgens) had its home on the edge of a staging area for road construction adjecent to the range being featured here. The vertical shoots of this member of the Heliantheae arise from short rhizomes
Laramie County, Wyoming. Mid-June; peak bloom stage.
262. Foothill flower on a gravelly spot- Top-down view (first slide) and two heads (second slide) of foothill arnica growing on the Laramie Plains near a mixed prairie range being grazed by cow-calf pairs. This individual grew on a gravel pile remaining following road construction. Hermann (1966, p. 290) concluded that foothill arnica has "but slight value as livestock forage".
Laramie County, Wyoming. Mid-June; peak bloom stage.
263. Shortgrass Plains disclimax- A mixed prairie in far-western edge of Central Great Plains degraded to nothing but buffalograss and plains pricklypear. Cause of thee severe retrogression and range depletion was not known. Overgrazing is always a "chief suspect", but it is also possible that some ignorant (and euqllly daring or super-optimistic) sodbuster tried his hand at raising wheat on this marginal land. Regardless of cause, this was disturbance climax on shallow-soil, "tight land" the climax range vegettion of which was blue gram-buffalograss shortgrass plains. Local patches of blue grama were still present as, for example, in the small depression at far right midground.
Although the present vegetation on this deteriorated range was shortgrass-pricklypear, and the potential natural or climax vegetation is still only shortgrass (iel classic "shortgrass plains", it was included at this location (as well as in the Shortgrass Prairie chapter) because of it close spatial proximity to the actual mixed prairie range types.
This was a different range site from that of mixed prairie shown in the immediately preceding slide, but its physical closeness to that range justified placement of this sample of shortgrass prairie in this location within the mixed prairie chapter.
Weld County, Colorado. Late June. FRES No. 38 (Plains Grassland Ecosystem). K-58 (Grama-Buffalograss).SRM 611(Blue Grama-Buffalo Grass). Degraded state of Grama "Short-Grass" Series, 142.12 of Plains Grassland biotic community, 142.1 Brown et al. (1998, p. 40). High Plains- Moderate Relief Plains Ecoregion, 25c (Chapman et al., 2006).
264. Central Plains mixed prairie- Another Central High Plains example of the needle-and-thread--blue grama--western wheatgrass cover type, in this instance with a nd sagebrsh (Artemisia filifolia) comprising a pronounced shrub component. Plains pricklypear and soapweed yucca were distant second- and third-place shrub species. Other important grasses included sand dropseed, buffalograss, sideoats grama, red threeawn, squirreltail bottlebrush, scattered individuals of sand bluestem, and, of course (though quite limited), cheatgrass. .In this early estival society the most common forb was prairie or western spiderwort (Tradescantha occidentalis). Scarlet globemallow was sporadic in occurrence. Other forbs at this season were incidential composites like the wavyleaf thistle (Cirsium undulatum) which is a nonweedy (on range), short-growing, native perennial.
This range was obviously in high Good to Excellent range condition class depending on which part of the vegetation one chose to evaluate.
Central Plains Experimental Station, Washington County, Colorado. Late June (early estival aspect). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006)
Transition grassland- The "tightland" or "hardland" mixed prairie of the Central Great (High) Plains with its various range sites is more diverse than it appears initially. The different grassland communities that developed in this semiarid continental climate are made up of various combinations of blue grama, buffalograss, western wheatgrass, sand dropseed, needle-and-thread, and green needlegrass. Miscellaneous other grasses included various bluegrass species, galleta, little bluestem, and little bluestem . The "sandyland" mixed prairie tends to have proportionately greater cover of midgrass species such as needle-and-thread, green needlegrass, and, of course, sand dropseed. There may also be more shrub cover on the grasslands that on soils higher in sand due to a more favorable soil water environment. This is most pronounced in the actual "sand hills" mixed prairie. Between these two general forms of mixed prairie, each of which has various range sites, there is a transition form of grassland--an ecotone--that itself has variations depending on soils, topography, aspect, as well as grazing history stretching to antiquity.
Some examples of this ecotonal form of mixed prairie were described in the following section.
265. Botanically rich mixed prairie- Landscape-scale perspective of an extremely plant species-rich mixed prairie in Central High Plains. On this cow-calf range major, native, perennial grass species included green needlegrass (Stipa viridula) and western wheatgrass which were co-dominants of this vernal society, blue grama, buffalograss, sideoats grama, silver bluestem, and few plants of sand dropseed.(ion that approximate order). There were some plants of the native annual grass, little barley, but very few plants of cheatgrass except in local disturbed areas such as around colonies of harvester ants and where spot grazing by cattle resulted in overgrazed microhabitats. Kentucky bluegrass (a naturalized, Eurazian perennial) grew on some of these locally disturbed patches of spot grazing that were less heavily grazed than those with kochia and cheatgrass.
Major forbs were in these disturbed microenvironments. The most abundant forb overall was the native scarlet globemallow. The associate forb (locally the second-most abundant on disturbed spots) was kochia (Kochia scoparia), a naturalized, Eurasian annual of the goosefoot family (Chenopodiaceae) or wild alfalfa or slender scurfpea (second-most abundant on undisturbed or less disturbed mini-locations).
This range was in high good to, probably, Excellent range condition class. It was a textbook example of the diverse range vegetation of climax mixed prairie.
As to taxonomy of this native vegetation this range plant community had the same designations as those described immediately above, but the Stipa species was different and there was not a shrub component on this variant of midgrass-dominated mixed prairie.
Washington County, Colorado. Mid-June (late vernal aspect; (peak standing crop of the vernal society). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
266. Height of the cool-season dominants- Peak standing crop of green needlegrass and western wheatgrass, cool-season co-dominants of a mixed prairie which also ncluded other native perennial grasses ranging from blue grama, buffalograss, sideoats grama, silver bluestem, and sand dropseed (in that relative order) as well as little barley, native annual grass, and the forbs, scarlet globemallow (the most sbundant), kochia, and wild alfalfa.
Local stands shown in these two "photoquadrants" were ungrazed being on highway right-of-way just outside the grazed range introduced in the preceding photographs. The vast bulk of biomass in this sward was green needlegrass and western wheatgrass: conservatively two-thirds to three-fourths of peak standing crop in the vernal society. In the estival or autumnal society dominated by warm-season season grasses (blue grama, buffalograss, sideoats grama,etc.) blue grama will be the dominant and provide a much greater proportion (percentage) of biomass as well as cover. In a really "mixed" mixed prairie like this one, dominance is season (society)-specific as well as site-specific. It seemed obvious that the greatest peak standing crop on this variant of mixed prairie would be during the vernal society because the two cool-season dominants are substantially larger (ranker-growing) than the dominant warm-season grasses plus these warm-season species had achieved much of their shoot growth by this time. For instance, buffalograss was in full-bloom and, though regarded as a warm-season shortgrass, was near its peak biomass.
This mixed prairie vegetation could be interpreted as classic mixed prairie not only on basis of tremendous botanical diversity and mix of cool-season and warm-season species, but also as to structure because green needlegrass of the stature attained on this range could be regarded as a tallgrass species. On some sites (and doubtless in drought years) green needlegrass barely attains mid-height and would be viewed as a midgrass, but at adult plant height of peak standing crop at time of these photographs green needlegrass stood over three to three and half feet tall. Green needlegrass can grow to heights equal to or greater than those of little bluestem (Shaw, 2008, ps. 231, 543)
Washington County, Colorado. Mid-June (late vernal aspect; (peak standing crop of the vernal society). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
267. Ain't all tall, green, and lush- Two examples of spot disturbance on the green needlegrass-western wheatgrass-blue grama-buffalograss mixed prairie cow-calf range introduced above. The first example (first slide) was at edge of a "bed" (colony) of western harvester ant (Pogonomyrmex occidentalis). The second example (second slide) was of heavy spot grazing by beef cattle. Major plant species at both degraded spots were scarlet globemallow (#1) and buffalograss (#2). In addition kochia was common near the entrance to the harvester ant nest.
Washington County, Colorado. Mid-June (peak bloom for both scarlet globemallow and buffalograss).
268. Cows prefer kochia- Selective grazing by cows and calves on green needlegrass-western wheatgrass-blue grama-buffalograss mixed prairie in the Central High Plains. This is the same cattle range described immediately above. In this "photoplot" cattle were able to exercise their preference for Kochia scoparia by grazing it to exclusion of scarlet globemallow and buffalograss. The latter two species grew immediately adjacent to (literally in contact with) kochia, which was consistently "topped" while scarlet globemallow and buffalograss were untouched.
Kochia is a now-naturalized, Eurasian, annual chenopod that is usually considered a weed particularily in regard to field crop production. However, it is well-known that kochia is a palatable forb. In fact, kochia is sometimes planted and grown as a forage field crop or managed as a self-seeding annual forage. On ranges, such as the one described here, kochia is frequently more palatable than many (if not most) native plants.
Kochia scoparia as an introduced forage species was treated in the chapter, Introduced Forages.
Washington County, Colorado. Mid-June (late vernal aspect; (peak standing crop of the vernal society). FRES No. 38 (Plains Grassland Ecosystem). K-57 (Grama-Needlegrass-Wheatgrass). SRM 608 (Wheatgrass-Grama-Needlegrass). Closest description in Brown et al. (1998, p. 40) was Cold Temperate Grassland 142, Plains Grassland 142.1, Mixed "Short-Grass" Series 142.13. High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
269. Tall and green on mixed prairie- Stand of green needlegrass (Stipa viridula) on a classic mixed prairie in Central High Plains. These plants were growing on highway right-of -way just a few feet outside the grazied range shown directly above.
Washington County, Colorado. Mid-June (peak standing crop of the vernal society; early bloom stage of green needlegrass).
270. Examples of green needlegrass- Plants of green needlegrass on green needlegrass-western wheatgrass-blue grama-buffalograss-sideoats grama mixed prairie in the Central High Plains. These plants were at their peak development of shoot and infloresecence. Some plants reached heights of three and half feet.
Washington County, Colorado. Mid-June; peak adult growth of plants.
271. Scan of shoots and panicles- Sexual shoots of green needlegrass (first slide) followed by panicles on these shoots. Spikelets were just beginning to bloom (most pre-bloom and some in anthesis).
Washington County, Colorado. Mid-June.
272. Doing their thing- Spikelets of green needlegrass in anthesis. Washington County, Colorado. Mid-June.
273. Now they're ready- Mature panicles of green needlegrass just before grain shatter.
Musselshell County, Montana. Mid-June (late spring); grain-ripe stage sust before seed-shatter.
There was no more difficult (and, perhaps, dubious) distinction between the grassland associaions of Clements (1920) than that of mixed prairie versus true prairie. This was not always a tenuous distinction, but it was downright arbitrary in certain areas where adjoining soil series or soil associations resulted in dramatically different--at least to the experienced "range eye"--grassland plant communities.
Shown below was one such example of a climax grassland community co-dominated by needle-and-thread and western wheatgrass. That combination was of itself unique because needle-and-thread thrives on sandy soils like those of some sandhills range sites whereas western wheatgrass does best on finner-textured (clay) soils. Soil texture classes like sandy clay or sandy clay loam provided ideal edaphic habitats for this combination of two cool-season grass species.
Given the arbitrary distinction of mixed prairie versus true prairie, this example was included in two Grassland chapters entitled 1) True Prairie and 2) Mixed Prairie-IA, Southern and Central Great Plains.
274. Two midgrasses and one herd of stockers- True or mixed prairie (depending on interpretation or perception) in the Central Great Plains co-dominated by western wheatgrass and needle-and-thread with blue grama as the associate. Also a "tad" of buffalograss. Even fewer plants of threadleaf caric sedge and sixweeks fescue. Main forb was wavyleaf thistle (first and third of these slides). Widely scattered plants of sand sagebrush.
The climax range vegetation was in the vernal society part of the annual cycle. It was at peak standing crop (or just past) of the two dominant cool-season, festucoid grasses. Some shoots of both co-dominants had turned the amber of their completed growth cycle for this year while other shoots were in progress to that growth or phenological stage. In the estival society phase to follow blue grama would mature to its peak standing crop, but this would be less than than that of the cool-season co-dominant grasses.
These three slides presented the landscape (and landscape-scale) along with physiogonomy of this climax range plant community (Excellent range condition class) which was being grazed by stockers (all steers).
Washington County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands Ecosystem). K-59 (Wheatgrass-Needlegrass). SRM 607 (Wheatgrass-Needlegrass). Loamy plains range site (Soil Conservation Service, 1986). High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
275. Range vegetation and range cattle up close- Three views of the internal structure and species composition of a climax true or mixed prairie (depending on interpretation of the viewer) in the Central Great (High) Plains. Needle-and-thread and western wheatgrass were the co-dominants while blue grama was the associate species of this Excellent range condition class grassland. Samd sagebrush (center foreground of third slide) added a woody (shrub) component but it was nowheree abundant to comprise a woody layer. Likewise the few widely scattered plants of plains pricklypear did not a shrub layer make. The principal (the only) forb was wavyleaf thistle (see the third of three slides in the immediately preceding slide-caption set).
The crossbred steers (roughly 650 pounds) were extremely gentle and curious. Steers came up to within two feet of the photographer, but would not lick his extended hand (these slides were taken using a 28mm lens so cattle were considerably closer than they appear). This author has found--in the vast majority of instances--that docile cattle and high-quality feed, high-successional stage range go hand-in-glove. The obvious explanation is that good husbandry, sound stewardship includes all range resources. This includes human and financial resources, but the author was not privileged to partake of these latter two categories.
Nice story. "All lived happily after ever" (at least until harvest time and end of the life cycle).
Washington County, Colorado. Mid-June; late vernal aspect. FRES No. 38 (Plains Grasslands Ecosystem). K-59 (Wheatgrass-Needlegrass). SRM 607 (Wheatgrass-Needlegrass). Loamy plains range site (Soil Conservation Service, 1986). High Plains- Flat to Rolling Plains Ecoregion, 25d (Chapman et al., 2006).
A need for clarification- Classification of mixed prairie--in fact, of Great Plains grasslands in general, remains in need of greater specification and explanation. Neither mapping of potential natural vegetation by Kuchler (1964, 1966) nor descriptions of rangeland cover types (Shiflet, 1994) were detailed or inclusive enough to include major, widespread climax range plant communities. The two major reasons for this are:1) intricate patterns edapho-topographic climaxes that would be difficult to present at the larger, more general (= zonal) mapping scales used and 2) climax types that have seasonal (essentially cool- and warm-season) dominants so that it is not possible to have accurate type designations when cover (dominance) type names include only dominants of one season (ie. cover type names include only dominant species of one phase of the annual growing season).
The Kuchler unit 58 or 65 (Bouteloua-Buchloe; Blue Grama-Buffalograss), depending on which map version of potential natural vegetation is used, is the largest and most obvious example of this problem. Blue Grama-Buffalograss is one of the largest of the Kuchler (1964, 1966) units, but within this regional (zonal) natural vegetation there are numerous units of potential natural vegetation of smaller size (spatial coverage) and, hence, greater difficulty of mapping that are dominated by other grass species. One of the more widespread and conspicuous of these is mixed prairie dominated by festucoid (cool-season) grasses such as needle-and-thread and/or Indian ricegrass on deeper, sandier soils and . Another range type dispersed within the regional Blue Grama-Buffalograss unit is Wheatgrass-Needlegrass (unit 59 or 66, including western wheatgrass-grreen needlegrass which, contrary to Kuchler (1964, p. 66), does include the latter in Colorado (see slides below).
These map units would appear as irregular-shaped, pokadot-like figures mostly within the surrounding regional blue grama-buffalograss vegetation, the "shortgrass country". In the terminology of Landscape Ecology Stipa-Oryzopsis units are patches in a matrix of Bouteloua-Buchloe. The floristically related Kuchler (1964, 1966) unit of 63 or 70 (Sandsage-Bluestem Prairie) was mapped near edges of and within the zonal shortgrass vegetation. This same general pattern would appear with smaller, but more numerous "spots" of Stipa-Oryzopsis if Kuchler (1964, 1966) had recognized this potential natural vegetation as a mapping unit. He did not (probably because he did not show units of vegetation at that small a mapping size or scale) though he did designate three units of potential natural vegetation which included Stipa comata as a dominant. (Kuchler, 1964; ps. 63, 64, 66). Likewise there would be smaller areas of map Kuchler unit 59 or 66 (Agropyron-Stipa) inside the unit 58 or 65 that also illustrated the problem presented by "islands" of one unit of potential natural vegetation within zonal- (= regional-) scale potential natural vegetation or, in context of the polyclimax or climax pattern theories, edapho-topographic climaxes within a climatic climax.
The problem presented by presence of two species of dominants or two sets of dominants (one for cool- and one for warm- growing seasons) in the same climax community was not addressed by Kuchler (1964, 1966). This phenomenon does not occur in many grassland cover types, but it is a feature of some dominance types and Kuchler units. One of these which was shown and described below had blue grama and buffalograss (eragrostoide grasses) as the warm-season dominants while needle-and-thread, sometimes, with Indian ricegrass (both festucoid grasses) were cool-season dominants. Some of the large area mapped by Kuchler (1964, 1966) unit 58 or 65 (Bouteloua-Buchloe) would be more accurately described as Stipa or Stipa-Oryzopsis (cool season)/Bouteloua-Buchloe (warm season). Such a lenghty designation (title) would appear awkward, but it would correctly show that dominance in such natural vegetation is by season (ie. has an aspect component). Influence (such as reaction in the Clementsian model) of some major range plant species would be more seasonal than yearlong. In this example, buffalograss presents something of a unique case because although it is an eragrostoid, and thus regarded as a warm-season, species it often has a bi-seasonal or opportunistic flowering pattern such that it blooms simultaneously with both needle-and-thread, Indian ricegrass, and/or western wheatgrass as well as with blue grama and some of the panicoid species like the bluestems. In such range vegetation buffalograss, the major sod-forming grass species, is an obvious dominant, especially when viewed as dominance (= cover) types where the criterion for dominance is plant cover, foliar or basal. The case for cover dominance is less obvious for bunchgrasses whether warm-seaon species like blue grama or cool-season species like needle-and-thread. With such cespitose species foliar or aerial cover, perhaps along with biomass (even if subconsciously), becomes more relevant. Nonetheless, there are clearly two-seasonal periods of dominance and two sets of dominants in certain grassland types, particular in mixed prairie where co-dominants are often a shortgrass and a midgrass species.
Another range type scattered--and not recognized-- through the Kuchler (1964, 1966) "shortgrass country" (unit 58 or 65; Bouteloua-Buchloe) was the prairie sandreed--needle-and-thread (Calamovilfa-Stipa) sandhills mixed prairie (Shiflet, 1994, p. ). In this rangeland type there is a a cool-season (festucoid) and a warm-season (eragrostoid) co-dominant. This is a textbook example that illustrated (in a most pronounced way) the phenomenon of aspect in range vegetation.
Frederic E. Clements clearly understood the aspect (seasonal) feature of vegetation. Aspect dominants or subdominants were shown in his vegetation classification scheme as the unit he labeled sociation or aspect society (Clements, 1936, p. 276). He explained that sociations were best developed in grasslands where seasonality is prominent with progression of the annual cycle from spring through autumn. There were commonly three sociations in mixed prairie for example. Dominants of the aspect society can be overall dominants when their presence (including during dormancy) is "controlling at all times" as for instance with some needlegrasses, wheatgrasses, and buffalograss (Weaver and Clements, 1938, p. 97).
In some Kuchler (1964, 1966) units of potential natural vegetation the aspect feature was critical to understanding the plant community, yet this feature was included only in description (perhaps in the list of "other [species] compnents") and not title of the unit. Importance of needle-and-thread, and even more so, Indian ricegrass in the "shortgrass country" (within the Bouteloua-Buchloe unit) was overlooked by Kuchler (1964, 1966) in the opinion of the current author. Unit 58 or 65 is considerably more diverse than mapped. Admittedly, it would be more difficult to map the spotted spatial pattern or mosaic of climax plant communities within this regional plains grassland than, by contrast, the long, narrow arrangement of forest vegetation in mountainous terrain. The fact remains that there are climax plant communities in the Southern and Central Great Plains that are dominated by needle-and-thread and/or Indian ricegrass which can be mapped as potential natural vegetation. Examples were presented in detail below. Indian ricegrass-dominated vegetation can be interpreted as semidesert grasslands so examples of this range type were cross-referenced in that chapter.
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