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test 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 andor 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 wheatgrss [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 paririe from an ecosystem perspective is that of Coupland (in Coupland, 1992, ps. 151-182).
Mixed Prairie-II includes sections devoted to miscellaneous aspects such as postclimax tallgrass prairie within the Mixed Prairie Region, Conservation Reserve Programs reseeded grasslands, and a section of playa lakes, including various characteristic species of these aquatic jewels of the Great Plains.
Tallgrass prairie that developed within the Mixed Prairie Region can be interpreted as postclimax vegetation by the monoclimax theory of F.E. Clements or as edaphic and/or topographic climax plant communities if viewed in the polyclimax theory of A. Tansley or climax pattern theory of R. Whittaker. By any of these theoretical perspectives tallgrass prairie is tallgrass prairi e and not mixed prairie. Tallgrass-dominated, climax grassland that developed as "successional islands" within a "sea" of mixed praire was included as part of the Mixed Prairie-II chapter as well as being included in the Tallgrass Prairie-II chapter. This duplicative arrangement was to facilitate finding of this range cover type by readers and to be consistent with organization as to regions based on physiographic provinces. Tallgrass Prairie within the regional Mixed Prairie is such extraordinary range vegetation that it certainly could not hurt to include it in two locations.
To the west of the tallgrass prairie and true prairie regions of the humid and subhumid zones scattered "islands" of actual tallgrass prairie developed on sandy soils and, especially, sand dunes in the sermiarid zone. An edaphic complex of interacting phenomena including deeper and coarse-grained soils, greater usable water capacity of these soils, increased nutrient cycling and organic matter content, and more mesic (perhaps more fertile) microsites due to microrelief of dunes combine to permit development of potential natural vegetation that is more typical of range plant communities that form on more favorable (more moderate or less harsh or extreme) environments.
In the Clementsian monoclimax (climatic climax; zonal or regional climax) model such natural plant communities that develop on habitats more favorable than that characteristic of a vast spatial region over geological temporal scale are regarded and classified as postclimax. In the Tansian polyclimax and the Whittaker climax pattern models, communities on extra favorable habitats are regarded as just another of several climaxes due to edaphic and/or topographic features more than those of the prevailing climate. The end result is the same. The different sematics (including dogma) and underlying conceptual views depend on whether the potential terminal plant community (successional endpoint) is interpreted over the time frame of theoretical geologic cycles and a predicted, ultimate peneplane (monoclimax theory) or in the shorter temporal scale of soil formation on existing land forms or topography (polyclimax or climax pattern theory).
In the descriptions and discussion that followed in this section the designation of postclimax was used in preference to (instead of) edaphic, topographic, or edapho-topographic climax. The rational, logical basis for this choice was direct and simple. First, the doctrine of priority (first in time; first in rights or first use equals first claim) awards the title to postclimax not some polyclimax-based designation such as edaphic climax. Second, postclimax was the term used in the earliest descriptions of tallgrass vegetation on dunes in the Great Plains which was by University of Nebraska ecologists under leadership of Charles E. Bessey (Roscoe Pound, Frederic E. Clements, and John E. Weaver were the pivotal founders of Plant Ecology). Out of the Nebraska school (through Clements and Weaver and, later, Weaver students) emerged monoclimax theory. The first theoretical explanations of grassland vegetation development on extra favorable habitats like dunes or wetlands was that of monoclimax theory (ie. postclimax) as postulated and published by Clements.
Some ecologists, including range scientists, included dune grasslands on which the dominants were tallgrass species as mixed prairie (vs. tallgrass prairie) or, at least, as part of the larger, surrounding mixed prairie. Like the situation of monoclimax vs. polyclimax or climax pattern theory, the end result is the same whether the perspective is 1) dune grassland as a form, expression, or range type of mixed prairie or 2) tallgrass prairie on dunes or deep sand within the mixed prairie region. This latter view was incorporated in the following treatment with due acknowledgement of the designation, mixed prairie, by some workers and in description of the rangeland cover type (Shiflet, 1994).
The postclimax tallgrass prairie has an obvious ecological aaffinity with the proximate--frequently adjoining--sand sagebrush (Artemisia filifolia)-tallgrasss or midgrass savanna and the sand shinnery oak (Quercus havardii) scrubland. This affinity is most clearly seen in shared key decreaser grasses most notably sand bluestem (Andropogon hallii= A. gerardii var. hallii). Sand sagebrush is a widespread shrub throughout much of the semiarid Great Plains vegetation. This woody composite is a conspicuous member of climax range plant communities, including postclimax tallgrass prairies on dunes and deep sands. Relative species composition (cover, density, biomass, general abundance) of sand sagebrush varies from trace to modest proportions so that there is a continuum from grassland with widely scattered shrubs to a grass-shrub savanna to a sagebrush scrubland with something of an herbaceous (grassy) understorey. These sand sagebrush shrublands are usually to almost always abnormal woody invasions indicating range retrogression (for causes ranging from inadequate frequency of fire through overgrazing to previous farming followed by field abandonment). Brush invasion on degraded ranges notwithstanding, presence of shrubs like sand sagebrush, various scrub cherries (Prunus spp.), plains pricklypear (Opuntia polycantha) and subshrubs such as broom snakeweed (Gutierrezia sarothrae) are natural components of climax vegetation-- at small propotions (percentages) of total plant cover and biomass.
1. Postclimax tallgrass prairie- Mixed prairie on deep sand in the Southern High Plains consisting of two layers: 1) a tallgrass overstorey dominated by sand bluestem (Andropogon hallii) with little bluestem and upland switchgrass as associate species and 2) a mid-grass understorey with needle-and-thread and sideoats grama as dominants along with traces of sand dropseed and blue grama. Blue grama is usually thought of (and was treated elsewhere herein as) a shortgrass species, but on this Deep Sand range site it attained a height approaching that of sideoats grama and it was so scarce that it did not comprise a shortgrass layer in this grassland vegetation. Sand sagebrush (Artemesia filifolia) also occurred in trace proportions such that it did not add a shrub layer. This vegetation was thus grassland and not a mixed grass-sagebrush shrub savanna (a form presented immediately below). Forbs were not abundant, but wild alfalfa (Psoralea tenuifolia) was present.
Scale of this tallgrass form of mixed prairie that developed in a 17 inch precipitation belt can be guaged by the four-foot barbed wire fence. Shoots of sand bluestem remaining (and broken) from the previous growing season extend above the top wire. The short shoot or "culmless" sand bluestem had just started to elongate it shoots and was still in the pre-boot stage during the current growing season.
The rolling sand dune microrelief of this range site was shown conspicuously by featuring a dune in extreme left midground. In the photograph the dune sloped down from left (top of dune) to right (bottom of dune) so that the base level of the dune was directly in front of the second steel post from the left side of the slide.
Mixed prairie postclimax grassland dominated by tallgrass species, especially sand bluestem, was discussed in Weaver and Albertson (1956, ps. 261-265, 295-299).
The concept of postclimax will be confusing to both beginning students and "climax" students who were not instructed or self-taught in the Clementsian paradigm. It is helpful-- if not essential-- for students to have some grasp of the concept of postclimax (and other aspects of the Clementsian model such as preclimax and disclimax) because so much of the seminal and classical work on range vegetation, especially that of grasslands, was interpreted and described in the language of the Clementsian lexicon. The sand bluestem-dominated mixed prairie range presented here was but one example.
Aside from the need to be fluent in the prevailing language in which most of North American vegetation was described, concepts like postclimax remain useful in providing a rational explanation for development and persistence of many North American range types. Postclimax tallgrass prairie and mixed prairie dominated by tallgrass species (like sand bluestem) is one of the textbook examples of this. At regional scale the Sandhills Region of Nebraska and Colorado is one of the largest remaining units of postclimax vegetation while smaller areas of sandhills prairie like that featured in this slide are outliers of postclimax plant communities. Readers were referred to Weaver and Clements (1938, ps. 82-83, 85-86, 102, 110, 462, 475, 520-521).
Clements (1936, p. 269) used the sandhills tallgrass as an example of postclimax, but in a pattern characteristic of Clement's writing he did not offer a concise definition of postclimax. Allaby (1998) did: "In the monoclimax model of climax vegetation development, communities differing from the climatic climax, owing to cooler and/or moister conditions than are characteristic of the regional climate". For example, soils of the Sandhills permit faster infiltration rates and greater absorption of precipitation to deeper depths in the soil profiles which allows development of vegetation more mesic than that which is typical for the general region of the High Plains. Grassland vegetation of humid and subhumid regions can develop in a semiarid region due to more mesic soil conditions, a function of coarser-textured soils.
Southern High Plains. Cimarron County, Oklahoma. July. FRES No. 38 (Plains Grassland Ecosystem). K-62 (Bluestem-Grama Prairie). SRM 720 (Sand Bluestem-Little Bluestem Dunes). Bluestem "Tall-Grass" Series of Brown et al. (1998). Deep Sand range site. High Plains- Rolling Sand Plains Ecoregion, 25b (Woods et al., 2005).
Developing "smack-dab" in the heart of mixed prairie there was, in Clementsian monoclimax thoery, a postclimax tallgrass prairie. In polyclimax theory of Tansley and climax pattern theory of Whittaker, this range vegetation would be interperted as an edaphic climax. This grassland that was more mesic than that of surrounding mixed prairie had developed on deep, sandy soil in what is known as the Great Bend Sand Prairie. Regardless of theoretical perspective, this tallgrass sand prairie was dominated by sand bluestem (Andropogon hallii) and with Indiangrass and switchgrass as associates. An example of this sand bluestem-Indiangrass-switchgrass prairie that was Excellent condition class was growing "just down the road" from the mixed prairie range stocked with heavy steers presented immediately above.
This postclimax, edaphic tallgrass prairie was included at this juncture to illustrate to students how vastly different range sites can be over remarkablly small distances and how this can result in different range cover types developing adjacent to each other. This example was also included in the postclimax tallgrass prairie portion of Mixed Prairie-II herein.
2. Bigger and taller grass on deeper sand- Postclimax tallgrass prairie dominated by sand bluestem with switchgrass, Indiangrass, sideoats grama as local associate species. Other abundant grasses included little bluestem and blue grama. The dominant forb in this early summer society was fineleaf or cutleaf hymenopappus (Hymenopappus filifolius). This range vegetation was essentially edaphically determined with the relatively deep sandy soil being conducive to a more mesic range plant community than that of adjoining mixed prairie that was presented in previous (above) photographs.
Kiowa County, Kansas. Late June (early estival aspect). FRES No.39 (Prairie Grassland Ecosystem) and K-66 (Bluestem Prairie) as a postclimax or a smaller-scale edaphic climax in a region the zonal vegetation of which is FRES No. 38 (Plains Grassland). This is problematic however because there is no Kuchler unit of tallgrass prairie in FRES No. 38. Itstead this was mapped as K-62 (Bluestem-Grama Prairie). SRM 721 (Sand Bluestem-Little Bluestem [Plains]). Bluestem "Tall-Grass" Series 142.11 in Plains Grassland biotic community 142.1 of Brown et al. (1998). Sands range site. Central Great Plains- Great Bend Sand Prairie Ecoregion, 27c (Chapman et al., 2001).
3. Skinny plainsmen- Columbia slimleaf, fineleaf hymenopappus, or cutleaf hymenopappus (Hymenopappus filifolius) was the major forb on this post-climax tallgrass prairie tht developed on deeper, sandy soil on the eastern portion of the Southern High Plains. Kiowa County, Kansas. Late June, peak bloom.
4. Edge of an island of tallgrass prairie in a High Plains "sea" of mid- and shortgrasses (with some scrub)- Two photo-plots of postclimax tallgrass (sand bluestem and little bluestem) prairie at the perimeter of a savanna of sand shinnery oak with sand bluestem and little bluestem that developed as an ecotone between tallgrass prairie and sand shinnery oak range ecosystems. At this point the savannah was to the rear with advance into the tallgrass prairie at peak standing crop and grain-ripe with onset of dormancy in bluestems.
This first slide featured the surface of the Tivoli deep sands soil. This slide was taken under a cloudless sky with full sun. The second of these photographs showed sand bluestem and little bluestem on the shallower Brownfield soil. This second photograph was taken under an overcast sky and showed the pale pubescence of bluestem inflorescences to advantage (but with less depth of field than in the full-sun shot). Here at the edge of grassland and away from savannah and, farther yet, shrubland the only shrub of much consequence was broom snakeweed, a local associate species. Another shrub, though one of much less cover and density than broom snakeweed, was sand sagebrush. Sagebrush was also present in the sand shinnery oak shrubland as seen above. Southwestern (Chyrsothamnus pulchellus) was a widely scattered shrub present in trace amounts in both the savanna and grassland and not, to any notable extent, in the shinnery oak range ecosystem.
Organization note: Viewers wishing to see changes in range vegetation from sand shinnery oak scrub duneland through the the ecotonal savanna to this tallgrass prairie can find the relevant photographs under Shrublands (Shinnery Oak).
Weaver Ranch, Roosevelt County, New Mexico. Autumnal aspect, October. Early dormancy and fruit-ripe pehnology of climax grasses. In theory this grassland would be (or could be seen as) FRES No.39 (Prairie Grassland Ecosystem) and K-66 (Bluestem Prairie) as a postclimax or a smaller-scale edaphic climax in a region the zonal vegetation of which is FRES No. 38 (Plains Grassland). This is problematic however because there is no Kuchler unit of tallgrass prairie in FRES No. 38. Itstead this was mapped as K-58 (Grama-Buffalograss). SRM 720 (Sand Bluestem-Little Bluestem [Dunes]). Bluestem "Tall-Grass" Series 142.11 in Plains Grassland biotic community 142.1 of Brown et al. (1998). High Plains- Llano Estacado Ecoregion, 25i (Griffith et al., 2006).
5. Postclimax prairie- Tallgrass prairie of sand bluestem and little bluestem in a semiarid zone in which the region climax range vegetation is mixed prairie and where there is far more "shortgrass country" than tallgrass range. This pair of photographs provided another study in light and color contrasts resulting from different conditions of natural light. The first slide (taken in full sun; under a completely cloudness sky) was of a stand of postclimax tallgrass prairie that was a consociation of sand bluestem, for all practical purposes the only grass species present in this stand. The shrub was broom snakeweed and the forb (a specimen in right, immediate foreground) was annual wild buckwheat (Eriogonum annuum). The second slide (under an overcast sky) featured a range community of more species diversity including sand bluestem, little bluestem, Indiangrass (Sorgastrum nutans), broom snakeweed, and annual wild buckwheat. In the instance of this second slide, grass panicles with their pale or silvery pubescence showed up to much better advantage under conditions of reduced light.
Range photographers frequently benefit from different light conditions depending on what aspects and characteristics they wish to feature. Atmospheric conditions with cloud cover that varies dramatically over a short period of time, while a source of aggravation if not frustration (especially with moment-to-moment light dynamics) to the shutterbug, is ideal for most kinds of range photography. These two photographs and the two in the preceding set provided examples of that lesson.
Anyway, this was a beautiful postclimax tallgrass prairie amid an otherwise "vast sea" of mixed prairie. Even the crotchiest ole range professor can fight at least half a semester's battle with university Pharisees treasuring scenes like these in his soul.
Weaver Ranch, Roosevelt County, New Mexico. Autumnal aspect, October. Tallgrass species were at pehnological stage of grain-ripe and beginning dormancy. In theory this grassland would be (or could be seen as) FRES No.39 (Prairie Grassland Ecosystem) and K-66 (Bluestem Prairie) as a postclimax or a smaller-scale edaphic climax in a region the zonal vegetation of which is FRES No. 38 (Plains Grassland). This is problematic however because there is no Kuchler unit of tallgrass prairie in FRES No. 38. Itstead this was mapped as K-58 (Grama-Buffalograss). SRM 720 (Sand Bluestem-Little Bluestem [Dunes]). Bluestem "Tall-Grass" Series 142.11 in Plains Grassland biotic community 142.1 of Brown et al. (1998). High Plains- Llano Estacado Ecoregion, 25i (Griffith et al., 2006).
6. In prairie and in scrub- Sand bluestem is the climax dominant grass (major decreaser) species on both postclimax tallgrass prairie (first or upper slide) and sand shinnery oak scrubland (second or lower slide). Shoots of sand bluestem in these (and above) photographs were in dormancy or near-dormancy stage with ripe grain. The associate species was the subshrub, broom snakeweed.
Weaver Ranch, Roosevelt County, New Mexico. Autumnal aspect, October. Early dormancy; grain-ripe phenology.
7. Details of the dominant decreaser grass- Sand bluestem was the dominant herbaceous species on sand shinnery oak duneland range (Tivoli deep sands) and co-dominant with little bluestem on tallgrass prairie that developed near shinnery oak shrubland.
Weaver Ranch, Roosevelt County, New Mexico. Autumnal aspect, October.
Sandhills postclimax tallgrass prairie on eastern High Plains- Shown and described in the following section was an example of sandhills tallgrass prairie at the eastern margin of the Southern High Plains. This example was on a low dune form of this range cover type on the Agricultural Research Service Southern Plains Experimental Range in Harper County, Oklahoma. The range vegetation described below differed from that above in being more of the sand dune shrub-grassland in contrast to grassland on sandy soil of nearly level land. This was the difference between sand sagebrush-tallgrass prairie described below versus tallgrass-midgrass prairie presented immediately above. In Kuchler units these two climax range plant communities were Bluestem-Grama Prairie (K-62) shown above and Sandsage-Bluestem Prairie (K-63) shown below. The example of K-62 was on the High Plains section of the Great Plains physiographic province whereas the example of K-63 was on the Plains Border section of the Great Plains (Fenneman, 1931, fold-up map), a section later described variously as the Rolling Red Hills, Rolling Redlands, Rolling Red Plains (Frye and Swineford, 1949; Schoewe, 1949, ps. 302-307).
The Society for Range Management rangeland cover type that best fit this range vegetation on basis of location (SRM 722; written by a Southern Plains Experimental Range scientist) described this as sand sagebrush-mixed prairie. R.Rosiere adhered to traditional (=Clementsian) views and interpreted this as this as postclimax tallgrass prairie. Alternatively--but with the same net conclusion--this general range plant community could be interpreted as an edaphic or edapho-topogrphic climax if viewed from the polyclimax theory of Arthur Tansley or climax pattern interpretation of Robert Whittaker. (See Whittaker [1951, 1953] for detailed critique of these various theoretical views of climax plant communities.)
SRM 722 was written broadly enough to include general sand hills rangeland north through northeastern Colorado and southwestern Nebraska. Obviously these latter sand hills forms or variants of SRM 722 (and not to be confused with Nebraska Sandhills tallgrass paririe, SRM 602) that are dominated by species like needle-and-thread (Stipa comata) are mixed prairie in the literal (the textbook) sense. Sand hills and sand dune forms or variants dominated by sand bluestem and switchgrass are another major range type altogether with the difference being nothing less than that of tallgrass prairie versus mixed prairie. From the current author's perspective SRM 722 could--and probably should--have been split to draw this distinction. At least it could be specified that there is a tTallgrass prairie vriant versus a mixed prairie variant of Sand Sagebrush-Prairie (ie. leave Mixed out of the title). Other than for specified areas or subregions (and some species differences), SRM 720 (Sand Bluestem-Little Bluestem, Dunes) was a more apt designation than SRM 722 (Sand Sagebrush-Mixed Prairie) for sand bluestem-dominated grasslands on duneland in the Rolling Red Hills. Relative cover of sand sagebrush--and in climax in contrast to deteriorated-- range plant communities was another critical issue as shown clearly in beginning the title of SRM 722 with " Sand Sagebrush" .
This vegetation was obviously in the mixed prairie association, but it was an island of tallgrass prairie therein. The flora included major species of short grasses (buffalograss, blue grama) and mid grasses (sand dropseed, sand lovegrass, western wheatgrass, sideoats grama), but the species composition and community structure were those of tallgrass prairie. This was especially true for most of the interdunal habitats which were generally dominated by sand bluestem, the upland form of switchgrass, and little bluestem. Vegetation of dunes was often a microsite shrubland of sand sagebrush and Chickasaw plum (Prunus angustifolia) and perhaps some plants of Oklahoma plum (P. gracilis).
Some of the less mesic interdunal habitats supported such cover of sand sagebrush as to be a savanna, generally with herbaceous layers comprising mixed prairie. The range vegetation presented here, however, was obviously (at least to this rangeman) as a tallgrass prairie form or phase of sandhills grassland. As such it was included in the chapter deveoted to interior tallgrass prairie.
8. Tallgrass prairie on the Southern Great Plains- General views of postclimax tallgrass prairie in the eastern Great Plains. Physiogonomy, structure, and growth or life form (tallgrass of sod-forming and/or cespitose habit, both monocotyledon and docotyledon shrub) of range vegetation and gently rolling to undulating relief (topography) of plains land form were presented. Sand bluestem and little bluestem were the most common grasses, but there was also silver bluestem, Canada wildrye, sideoats grama, tumblegrass, western wheatgrass at local scale, and even patches of blue grama and buffalograss. Forbs were uncommon, but two species with a conspicuous presence were spectacle-pod (Dithyrea wislizenii var. palmeri) and thickleaf or aridland goosefoot (Chenopodium pratericola). Illinois bundleflower was also present but at lower density, cover, etc. than spectacle-pod and thickleaf goosefoot. Soapweed yucca (Yucca glauca) and sand sagebrush were present though infrequent on this pristine example of postclimax or edapho-topographic climax grassland.
More details of species composition and general aspects of the range environment followed in subsequent photographs and captions.
Southern Plains Experimental Range, Harper County, Oklahoma. Late June; late vernal to early estival aspect. FRES No. 39 (Prairie Ecosystem). K-63 (Sandsage-Bluestem Prairie). SRM 722 (Sand Sagebrush-Mixed Prairie) and/or SRM 605 (Sandsage Prairie): two competing rangeland cover types or two slightly different titles and descriptions of the same or very similar range vegetation. Bluestem "Tall-Grass" Series, 142.11 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Central Great Plains- Rolling Red Hills Ecoregion, 27q (Woods et al., 2005).
9. More views- Range landscape and vegetation of postclimax tallgrass prairie on the Rolling Red Plains. Sandy soil and sand dunes provided an environment for grasses and shrubs that was more favorable (moister soil, more moderate microclimate) than that of range habitats which were more typical of this eastern margin of the Great Plains (the Plains Border section). More prominent relief (by Great Plains standards) and deeper rooting medium made for a more mesic and generally milder range environment which in turn resulted in development of a range plant community comprised of grasses having larger mature size (eg. tallgrass species such as sand bluestem, little bluestem, and switchgrass) and higher proportions of woody plants (greater crown cover of shrubs like sand sagebrush and Chickasaw plum). Hence, this has traditionally been interpreted as postclimax vegetation.
The first of these two photographs presented postclimax vegetation in an interdunal space, a fairly level land surface situated among sand dunes. Range vegetation in the local interdunal area was a dense stand of warm-season tallgrasses (switchgrass, sand bluestem, and little bluestem were all prominent) along with Canada wildrye and Illinois bundleflower. The two most conspicuous and generally most abundant forbs were spectacle-pod and thickleaf goosefoot. The second photograph showed another interdunal area (foreground) leading with an ever-so-gently elevational rise to a sand dune (background). In this second slide sand sagebrush joined the lineup of grass species listed for the first slide. Details of range vegetation on dunes followed in subsequent slides.
Southern Plains Experimental Range, Harper County, Oklahoma. Late June; late vernal to early estival aspect. FRES No. 39 (Prairie Ecosystem). K-63 (Sandsage-Bluestem Prairie). SRM 722 (Sand Sagebrush-Mixed Prairie) and/or SRM 605 (Sandsage Prairie): two competing rangeland cover types or two slightly different titles and descriptions of the same or very similar range vegetation. Bluestem "Tall-Grass" Series, 142.11 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Central Great Plains- Rolling Red Hills Ecoregion, 27q (Woods et al., 2005).
10. Studying range vegetation on the way to and at base of a sand dune- A synopsis view of postclimax tallgrass paraire on sandy land in the Plains Border section at eastern edge of the Great Plains was presented in the first of these two photographs. Sand bluestem, a decreaer tallgrass, was the overall dominant of the range presented here. Little bluestem and switchgrass were typically associate species except for local environments where they were dominant, even exclusive, species. Other grasses included Canada wildrye, silver bluestem, sand dropseed, sideoats grama, tumblegrass, blue grama, and buffalograss. The grass stand in foreground to midground of this first slide was so dense and with such heavy foliar cover of grass that there were almost no forbs present except for Illinois bunmdleflower. Shrubs were almost totally absent in this dense grass stand.
The second "photo-quadrant" included an east slope of a big circumference sand dune and a large interdunal area to the immediate right and rear of the featured slope of the dune. Even here on a hummocky low dune on edge of the High Plains, an east slope (even if just a slight inclination) was more mesic than adjacent microhabitats (environments formed by microrelief). The small patch of woody vegetation was mostly Chickasaw plum with sand sagebrush, the more xeric shrub, the associate species. At toe slope of the dune range vegetation (foreground) there was a local combination of Chickasaw plum and herbaceous plants with shoots of sand bluestem prominent. Other herbaceous species included the naturalized annual brome, Japanese chess, and western ragweed. The interdunal space was co-dominated by sand bluestem and the upland form of switchgrass.
There was a tremendous crop of biomass on this range, especially on the interdunal areas. This much standing crop was produced in a location receiving about 20 inches of average annual precipitation.
Southern Plains Experimental Range, Harper County, Oklahoma. Late June; late vernal to early estival aspect. FRES No. 39 (Prairie Ecosystem). K-63 (Sandsage-Bluestem Prairie). SRM 722 (Sand Sagebrush-Mixed Prairie) and/or SRM 605 (Sandsage Prairie): two competing rangeland cover types or two slightly different titles and descriptions of the same or very similar range vegetation. Bluestem "Tall-Grass" Series, 142.11 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Central Great Plains- Rolling Red Hills Ecoregion, 27q (Woods et al., 2005).
11. Studying range vegetation on a sand dune- Local stand of postclimax scrub on a sand dune in the Rolling Red Plains. This floristic cast featured woody dominants supported by herbaceous understudies. The first of these two slides showed most of a sand dune (the side and summit) that was typical for duneland range in this area. Sand sagebrush dominated sides of the dune while tallgrasses maintained control of soil at foot of the dune and Chickasaw plum (possibly some Oklahoma or slender plum) slightly edged out sagebrush to be "king of the hill" (or, rather, "of the dune").
Note on Prunus species: according to Atlas of the Flora of the Great Plains (McGregor et al., 1977) it was possible that there was both Chickasaw plum (Prunus angustifolia) and Oklahoma plum (P. gracilis) on sand dunes at Southern Plains Experimental Range.
The second slide featured the summit (if such term would apply) of the same dune. On this upper part of the dune plum was slowly pushing sand sagebrush downhill. Sand bluestem was the most abundnt grass and could be interpreted as an herbaceous associate species. Interesting biodiversity, including species and life or growth forms. Both woody and herbaceous plants were climax dominants on the range habitat of dunes, at least at roughly the compositions and locations shoen here. This would make for an interesting--though simple--gradient analysis.
Southern Plains Experimental Range, Harper County, Oklahoma. Late June; late vernal to early estival aspect. FRES No. 39 (Prairie Ecosystem). K-63 (Sandsage-Bluestem Prairie). SRM 722 (Sand Sagebrush-Mixed Prairie) and/or SRM 605 (Sandsage Prairie): two competing rangeland cover types or two slightly different titles and descriptions of the same or very similar range vegetation. Bluestem "Tall-Grass" Series, 142.11 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Central Great Plains- Rolling Red Hills Ecoregion, 27q (Woods et al., 2005).
12. Savanna form of postclimax sand sagebrush-tallgrass vegetation- Two views of Great Plains deep sand and dunes where warm-season tallgrassess (sand bluestem, little bluestem, and upland switchgrass) and miscellaneous other grass species (Canada wildrye, sand dropseed, silver bluestem, sideoats grama, blue grama, buffalograss, and Japanese chess) with sand sagebrush as the woody (shrub) component formed a savanna. This range plant community was postclimax when interpreted from monoclimax theory and/or an edaphic or edapho-topographic climax when viewed from polyclimax theory. Forbs were neither common nor indicator species. The two main (if uncommon) forbs were spectaclepod and thickleaf goosefoot. Illinois bundleflower ran a distant third.
In this range type and in this area in the Plains Border section at far eastrn edge of Great Plains there exist a continuum with regard to cover and density of sand sagebrush extending from a savanna with the dominant tallgrasses and grass species to a sand sagebrush shrubland with very little to almost no herbaceous understorey. The latter vegetation almost always indictes a highly degraded range that is often viewed as a disturbance climax in which range improvements (brush control and, often. range reseeding) are required to restore such depleted ranges.
The savannah form of range plant communities on Great Plains dunes and deep sand is often the potential natural vegetation (ie. postclimax range vegetation). That form or variant of duneland range vegetation with widely scattered plants (often local, fairly dense yet widely spaced stands) of sand sagebrush with even greater density and cover of decreaser tallgrasses was shown in these two photographs. Students will note that the sand bluestem was growing inside local stands of sand sagebrush where this dominant species stood taller than its climax shrub associate. It was underscored that sand sagebrush was climax at the approximate proportions (density, cover, biomass) of the range vegetation in these "photo-plots". A range plant community consisting primarily of sand sagebrush--a sagebrush scrubland or shrubland--constitutes a disclimax, especially when not "accompanied" by tallgrasses like sand bluestem, little bluestem, and switchgrass.
Southern Plains Experimental Range, Harper County, Oklahoma. Late June; late vernal to early estival aspect. FRES No. 39 (Prairie Ecosystem). K-63 (Sandsage-Bluestem Prairie). SRM 722 (Sand Sagebrush-Mixed Prairie) and/or SRM 605 (Sandsage Prairie): two competing rangeland cover types or two slightly different titles and descriptions of the same or very similar range vegetation. Bluestem "Tall-Grass" Series, 142.11 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Central Great Plains- Rolling Red Hills Ecoregion, 27q (Woods et al., 2005).
13. Sand country herbaceous cast- Composite views of major grass species on postclimax tallgrass prairie on semiarid duneland. Range vegetation featured here was in an interdunal space. Sand bluestem was the main grass species that made up most of plant cover in first photograph and was featured at shorter focl length in second photograph. Large shoots (including some of last year's mature-sized ones in first slide) and the unique light gray-green color set off sand bluestem from all other grasses. Some of the other grass species included an upland form (ecotype) of switchgrass, nodding or Canada wildrye, little bluestem, sand dropseed, buffalograss, and blue grama. Not all of these grasses were discernable in these two slides, but structure of this range vegetation and close-distance physiogonomy of it were presented, as they were representative of this postclimax tallgrass prairie.
An argument could be made that the species composition and architecture/structure of this range vegetation was a form of mixed prairie given the combination of tallgrass species like sand bluestem and switchgrass with shortgrasses such as blue grama and buffalograss. There were at least two glaring facts that weakened such an argument: 1) tallgrass species overwhelmingly dominated the vegetation and made up a disproportionately large percentage of the species composition based on biomass, foliar cover, physiogonomy (including aspect dominance), and even shoot density and 2) midgrasses like sideoats grama and western wheatgrass that are typically major charactaeristic components of mixed prairie were the least abundant group of grass species present on this range.
Southern Plains Experimental Range, Harper County, Oklahoma. Late June; late vernal to early estival aspect. FRES No. 39 (Prairie Ecosystem). K-63 (Sandsage-Bluestem Prairie). SRM 722 (Sand Sagebrush-Mixed Prairie) and/or SRM 605 (Sandsage Prairie): two competing rangeland cover types or two slightly different titles and descriptions of the same or very similar range vegetation. Bluestem "Tall-Grass" Series, 142.11 of Plains Grassland biotic community, 142.1 (Brown et al., 1998, p. 40). Central Great Plains- Rolling Red Hills Ecoregion, 27q (Woods et al., 2005).
Note on orgainzation: Mixed prairie range (eg. climax vegetation dominated by needle-and-thread, blue grama, sideoats grama) in the sand hill area of the Central Great Plains were included in the Mixed Prairie chapter (also under the Grassland heading) of Range Types.
14. Basal shoots of sand bluestem (Andropogon hallii)- Examples of lower shoots (just above rootcrown) of sand bluestem growing on sandhills postclimax (= edaphic climax) tallgrass prairie in the Southern High Plains. Sand bluestem was the overall (and the defining) dominant tallgrass species of this climax prairie community. Little bluestem and switchgrass (upland form) were the associate tallgrasses with either of these species sometimes being the local dominant. These examples presented typical early season coloration of sand bluestemt along with close-up views of leaf blade and sheath. Note prominent parallel leaf veination.
Southern Plains Experimental Range, Harper County, Oklahoma. Late June; mid pre-bloom phenological stage.
15. A little higher up- Details of leaves and clum of sand bluestem growing on a sandhills postclimax (= edaphic climax) tallgrass prairie in eastern margin of the Southern Great Plains. Details of leaf collar and sheath were emphasized in this slide.
Southern Plains Experimental Range, Harper County, Oklahoma. Late June; mid pre-bloom phenological stage.
16. Goosed in the dunes- Thickleaf or aridland goosefoot (Chenopodium pratericola) growing in an interdunal area in postclimax tallgrass prairie in the southern sandhills of the Southern Great Plains. This specimen was growing on a range that could be described as a sand sagebrush-tallgrass savanna. Part of this postclimax range vegetation was dominated by sand bluestem and upland switchgrass whereas other local areas consisted mostly of mid- and shortgrass species or, on tops of sand dunes, scrub of sand sagebrush and wild plum. Thickleaf goosefoot is one of several Chenopodium species in the Great Plains Region, almost all of which (including this species) are annuals and of moderate palatability to range animals including grass -feeders like cattle. C. pratericola was a locally dominant forb in this deep sand vegetation.
Southern Plains Experimental Range. Harper County, Oklahoma. Late June.
17. Spectacle-pod (Dithyrea wislizeni= Biscutella wislizeni)- Spectacle pod is not only one of the most apt-named range plants it is also one of most common species of the Cruciferae native to the ranges of the Southern Great Plains and Tran-Pecos Basin and Range. Coulter (1891-1894) wrote of this species as native to the Staked Plains (High Plains portion of the Southern Great Plains) and sandy soils along the Rio Grande. Wooton and Stanley (1915) presented the species range as from Colorado and Utan to west Texas and south into the Mexican states. Spectacle-pod is thus a species of both Mixed Prarire and Shortgrass Plains grasslands as well as of the Chihuhuan Desert,It is especially abundant in the shinnery oak (Quercus harvardii) shrubland ecosystem and, at somewhat lesser cover and density, in the postclimax tallgrass prairie of the Southern Great Plains. Spectacle-pod has a high preference for habitat with sandy soils.
Spectacle-pod appears to have a very versatile life cycle having been described by various taxonomists as annual, biennial, or perennial. This pattern of resource allocation is characteristic of plants of harsh habitats. Whle conducting reserch for his Master's thesis this author found spectacle-pod to one of the most densly populated of the larger forb species on the disclimax Chihuhuan Desert of the New Mexico State Universtiy College Ranch. This was during a period (the years of 1972-1973) of average or higher precipitation. Sebsequent visits to the same study ranges of the College Ranch following dry periods and severe drought revealed little and no evidence, respectively, of this cricifer. These findings were consistent with an opportunistic range species.
The specimen shown here was growing in a typically dense population in a sand shinnery oak (Quercus haavardii) shrubland in which there had been a recent surface fire. (Note small shinnery oak resprouts.)
Beckham County, Oklahoma. June.
18. Inflorescence and fruit of spectacle-pod- The fruit type of is a silique, defined by Smith (1977, p. 307) as a broad, longitudinally dihiscent fruit in which fruit walls part from a persistent internal partition called the replum.
The photographs of the flower cluster showed the prominent and clearly separate or unjoined four petals of the corolla.
Beckham County, Oklahoma. June.
19. Playa lake in High Plains mixed prairie -a natural wetland whose range community is dominated by tobosagrass (Hilaria mutica) with western wheatgrass, sidoeots gramma, inland saltgrass and buffalograss. Union County, New Mexico. July. FRES No. 38 (Plains Grasslands Ecosystem). No Kuchler unit (another unit too small to be included in Kuchler map, but it can be interpreted as a local (playa) variant of K-61 (Wheatgrass-Grama-Buffalograss). Southern variant of SRM 615 (Tobosa variant of Wheatgrass-Saltgrass-Grama) Southwestern Tablelands- Upper Canadian Plateau Ecoregion, 26l (Omernik and Griffith, 2006).
20. Playa vegetation- Zonation of wetland vegetation was pronounced in this range plant community. This was shown in the first photograph. Details of the most lakeward-- the actual aquatic-- vegetation was presented in the second photograph. Dominance around playas often varies at local scale, even micro-scale. That was the case for playa vegetation presented here. The most common or overall dominant species was western wheatgrass. There was a species of spikerush (Eleocharis sp.) that was a local dominant. There were several species of sedge (Carex spp.) plus at least one species of rush (Juncus sp.), but none of these had produced inflorescences or fruit. Species of Carex and Eleocharis can only be postively from fruits.
One of the most abundant and conspicuous forbs was bur ragweed, lakeweed, or woolly-leaf bursage (Ambrosia grayi= Franseria tomentosa= Gaetnera tomentosa). This species was not blooming and from a distance (as in these photographs) it could be confused with silveleaf nightshade (Solanum elaeagnifolium) which was also present at much lower density and cover. Curly dock (Rumex crispus), a Eurasian weed, was locally abundant.
There were undoubtedly various other species, especially of forbs, that were not in flower and could only be identified by someone having enough familarily with playa flora to be able to recognize these range plants at immature stages.
Potter County, Texas. June, early estival aspect. FRES No. 38 (Plains Grassland Ecosystem). K-61 (Wheatgrass-Grama-Buffalograss). Southern Hihg Plains variant of SRM 609 (Wheatgrass-Grama). No appropriate Series in the Brown et al. (1998) Plains Grassland biotic community. Playa subunit of High Plains- Ilano Estacado Ecoregion 25i (Griffith et al., 2004).
21. Mesic mixed prairie disclimax- Overgrazing at perimeter of a playa lake converted the local climax western wheatgrass-vine mesquite mixed prairie community into a buffalograss-dominated shortgrass community with blue grama and silver bluestem as associate species. Major forb was annual broomweed (Gutierrezia dracunculoides); not conspicuous because it was at pre-bloom stage. This was a sacrifice site (a range site that is intentially, probably unavoidably, overgrazed in order to get efficient use out of the rest of the range) by nature of it's existence at edge of this "aqueous jewel of the plains".
Presence of a sacrifice site in this situation is not mismanagement. This photograph was presented as a comparison to the succeeding one to illustrate how grazing-- the phenomenon of selective grazing-- can affect species composition of ranges. Next slide please.
Carson County, Texas. Early estival aspect, June. FRES No 38 (Plains Grassland Ecosystem). K-61 (Wheatgrass-Grama-Buffalograss). SRM 609 (Wheatgrass-Grama). No appropriate Series within the Brown et al. (1998) Plains Grassland biotic community. Playa subunit of High Plains- Llano Estacado 25i (Griffith et al., 2004).
22. Mixed prairie grassland co-dominated by western wheatgrass and vine mesquite- A barbed wire fence separated this range from that shown in the preceding slide. Heavy grazing by cattle of the climax or potential natural vegetation growing adjacent to a playa lake resulted in range retrogression as shown immediately above. This was a textbook example of selective grazing. Grazing cattle removed more plant tissue (photosynthetic area, apical meristem, etc.) from the taller mid-grasses with their upright growth than from low-growing shortgrass species like buffalograss. Students should bear in mind that most shoots of both buffalograss and vine mesquite are stolons. Western wheatgrass is a rhizomatous, sod-forming grass while blue grama is a bunchgrass whose shoots are tillers. In this case it was height of grasses and not form of shoot or plant growth form that resulted in shifts in species composition. There may also have been some influence from cattle preferences for the different species, but this was undoubtedly less important than grass morphology in this specific instance.
Colony of western wheatgrass in foreground; vine mesquite, background.
Carson County, Texas. Early estival aspect, June.
The following sequence of three photographs were of zones of range vegetation in a playa (lake was dry though soil in bottom of basin was still muddy) extending from bottom to lip or edge of lake. Following this photographic sequence of vegetational zonation various species of range plants growing in this playa were presented. Autumn (early October) so examples of plants ranged from flowering and fruit-set to dromancy depending on species.
Randall (deep clay) was the predominant soil series on which range vegetation of this playa had developed. The playa itself had formed over and extended downward toward the Blackwater Draw formation. The Blackwater formation and related details of Lubbock Lake was described and explained variously by Carlson (2005; see esp. ps. 21-24). The Lubbock County soil survey (Soil Conservtion Service, 1979) did not delve into geological formations but did provide descriptions of Randall clay. Also Figures 1 and 2 (SCS, 1979, p. 56) were useful to show general relief as related to playas in this area.
23. Autumn vegetation in a dry playa- A photo-transect from near the bottom of a dry playa to its upper boundary (or lip) revealed zones of range vegetation made up of populations of various plant species. From foreground (bottom of lake) to background (lip or rim of playa) species of range plants were (in approxomate or general sequence of encounter): pink smartweed or long-styled knotweed (Polygonum bicorne), bur ragweed or woolyleaf bursage (Ambrosia grayi= Franseria tomentosa), prairie coneflower or Mexican hat (Ratibida columnifera= R.columnararis= Rudbeckia columnaris= R. columifera), annual sunflower (Helianthus annuus= H. aridus), horseweed or mare's-tail (Conyza canadensis= Erigeron canadensis), common cocklebur (Xanthium strumarium), and kochia or summer cypress (Kochia scoparia).
There were for all practical purposes few to almost no grasses in the range vegetation in the actual playa or along this inner bottom-to-top slope except for scattered large plants of blue grama and Arizona cottontop. The more common and dominant species of grasses at top of and above the playa pe se included blue grama, buffalograss, Arizona cottontop, common windmillgrass, purple threeawn, sideoats grama, and Johnsongrass. Honey mesquite was also well distributed aabove the playa.
Texas Tech University campus playa, Lubbock County, Texas. October, autumnal aspect. Various advanced stages of plant phenology depending on species.
24. Greater detail- Zooming in on the zones of playa vegetation introduced in the preceding slide. Foreground and most of midground was an extensive colony of pink smartweed or long-styled knotweed with some prairie coneflower. Right midground was bur ragweed. Background was predominately annual sunflower but with considerable cover of horseweed or mare's-tail, cocklebur, and kochia.
Playa was dry at time of photograph, but photo-point was from near center of bottom of lake so that outward zones were those requiring lesser amounts of soil water.
Texas Tech University campus playa, Lubbock County, Texas. October, autumnal aspect. Various advanced stages of plant phenology depending on species: pink smartweed was in full-bloom, bur rageweed or bursage and common cocklebur were at ripe fruit stage, and most annuals like horseweed, annual sunflower, and kochia were dead with fully ripe, shedding fruit.
25. Some of this and some of that- Outward and upward from the inner-most "ring" of playa vegetation dominated by pink smartweet with much less of the associated Mexican hat or prairie coneflower featured in the immediately preceding slide was a zone comprised exclusively of bur ragweed or woolyleaf bursage. The third (higher or upper and least mesic) major vegetational zone was a mixed stand of annual sunflower (the most common or abundant species), horseweed, cocklebur, and kochia.
Texas Tech University campus playa, Lubbock County, Texas. October, autumnal aspect. Various advanced stages of plant phenology, but most of the annuals (horseweed or mare's-tail, annual sunflower, kochia) were dead and shedding ripe fruit.
26. Bur ragweed or woolyleaf bursage (Ambrosia grayi= Franseria tomentosa)- A few entire (above portions) plants of woolyleaf bursage at peak standing crop and fruit-ripe. All the Ambrosia species are monecious with separate staminate and pistillate heads. Some Ambrosia species are annual while others like A grayi are perennial. Woolyleaf bursage is a species of wet (at least seasonally so) habitats like playa lakes, buffalo wallows and other depressions. Bur ragweed has immense rootstocks from which it often forms extensive colonies such as shown in the preceding photographs. These are clonal colonies with each shoot being a ramet or module of the original genetic parental plant.
The combination of asexual (vegetative) and sexual reproduction (see next set of slides for an example of the prolific seed production of this species) makes it an aggressive, hard-to-control weed on cropland (Whitson et al., 1992, ps. 48-49). It is, however, a native plant important in erosion control and feed for concentrate feeding animals, particularily birds.
The characteristic light gray color of bur ragweed is due to it fuzzy pubescence, hence the adjective, woolyleaf, included in some of the common names for this species.
Texas Tech University campus playa, Lubbock County, Texas. October, fruit-ripe stage of phenology.
27. Brown burs and gray leaves- Details of shoots, including general view of fruit, of bur ragweed or woolyleaf bursage. The fruits (from pistillate flowers of this monecious species) were visible in leaf axils of the second of these slides.
Texas Tech University campus playa, Lubbock County, Texas. October, fruit-ripe stage of phenology.
28. A crude bouquet- Tall and rather rank plants of pink smartweed and bur ragweed growing together at micro-scale edge of two zones of range vegetation in a playa. This gave an example of the relatively large size of pink smartweed or, as it is sometimes known, long-styled knotweed.
This is an annual species (as were most of the plant species and most of phytomass in this playa) that is so well-adapted to disturbance environments that it has been interpreted as "a first year invader (Correll and Correll, 1975, p. 823). There are several species of Polygonum adapted to moist and wet habitats of the central and southwestern grasslands, including mixed prairie. (Correll and Correll [1975, ps. 807-834] described 23 species for the four states of Oklahoma, Teaxs, New Mexico, and Arizona. Correll and Johnston (1979, ps.510-523) recognized 10 Polygonum species for Texas, but they (Correll and Johnston, 1979, ps. 523-526) also retained the genus Persicaria with 11 species whereas other authors included Persicaria under Polygonum. Thus in the flora of Texas vascular plants pink smartweed (the reported common name) was shown as Persicaria bircorne (Correll and Johnston, 1979. ps. 524-525). D.S. Correll was the senior author of both of these manuals that were published in the same decade. "Go figure", as they say.
Haukos and Smith (1997.p. 141) interpreted P. birorne and P. pensylvanicum as one species. This author did not encounter any other authorities that followed this interpretation. Nor did he. P. pensylvanicum was presented farther below. (Incidentially, P. pensylvanicum also has been referred to as pink smartweed, but even though the adjective "pink" is appropriate it was herein recommended that the common name of Pennsylvania smartweed be reserved for the rmore obvious r P. pensylvanicum, the species with that specific epithet.)
Texas Tech University campus playa, Lubbock County, Texas. October.
29. Shoot of pink smartweed- Upper portion of shoot of pink or long-style smartweed, one of several Polygonum species common in mesic or wet areas on the Southern High Plains in the heart of the mixed prairie.
Texas Tech University campus playa, Lubbock County, Texas. October.
30. Pink details- Close-up views of the inflorescence of pink or long-style smartweed. An interesting floral feature of Polygonaceae is that its species lack a corolla and have a petaloid calyx (Smith, 1977, p. 112). The pretty floral bracts seen here are sepals not petals. The inflorescence has been interpreted as a raceme, spikelike raceme, or spikelike panicle (Smith, 1977, p. 112; Correll and Johnston, 1979, ps. 519, 523). The fruit is a an achene (Smith, 1977, p. 112) which is used as a concentrate feed by birds, including waterfowl and songbirds (Martin et al., 1951, p.449-450). Valuable wildlife feed plant.
Texas Tech University campus playa, Lubbock County, Texas. October.
The following sequence of photographs were of various range plant species that frequently grow in or near playa lakes on the Southern High Plains (Staked Plains or Llano Estacado portion of Great Plains).
31. Colony of pale smartweed (Polygonum lapathifolium)- Pale smartweed species is a widely distributed Polygonum species. Wetlands are not uniform in all aspects of their environment, but the presence of mostly perennial standing water on the land is a unifying feature. Several Polygonum species, including pale knotweed or smartweed, are thus widespread in their distribution owing to this common feature. This fine colony of pale smartweed was growing in a slough on the Modoc Creek watershed in Ottawa County, Oklahoma. August.
32. Pale smartweed- Details of shoots and flower cluster of pale knotweed growing in a drainage into Modoc Creek in Ottawa County, Oklahoma. August.
33. Pennsylvania or pink smartweed or knotweed (P. pennsylvanicum)- Here was another poisonous one . Pink smartweed is not a major toxic range plant but problems can occur (Kingsbury, 1964, ps. 229-230, Burrows and Tyrl (2001, p. 980-982), and Hart et al. (2003, ps. 154-155). Knotweed originated from the swolen nodes of the rhizomes from which acventitious roots and new shoots arise. Smartweed alluded to a somewhat stinging sensation when running bareleggged througth the dense colonies of Polygonum (or from schoolboys slapping each other with the shoots in which any- and everything would sting).
Pennsylvania or pink smartweed is widely distributed in moist lowlands throughout moist lowlands of the Great Plains and Central Lowlands physiogrphic provinces. On the semiarid High Plains section of the Great Plains some of the most common moist habitats are playas. Another species (P. bicorne) is also frequently called pink smartweed. Haukos and Smith (1997, p. 141) interpreted P. bicorne and P. pennsylvanicum as the same species, but this author was not able to find any other authorities who followed this treatment. Both species are annuals. A particularly good treatment of P pennsylvanicum, especially with regard to wetlands, was Correll and Correll (1975, p. 819-820). Fassett (1985, p. 205) followed earlier taxonomic tratements and split P. pennsylvanicum into five varieties with several forms under some of those. Splitters!
It was reported above (under pink smartweed) that Correll and Johnston (1979, ps.519-526) in the bible of Texas vascular plants split the smartweeds or knotweeds into two genera so that they recognized 10 Polygonum species and 11 Persicaria species for Texas. Most other authors included Persicaria under Polygonum. This latter included Corrrell and Correll (1975). D.S. Correll was the senior author of both manuals (Correll and Correll, 1975; Correll and Johnston; 1979). Thus in the flora of Texas vascular plants Pennsylvania smartweed was shown as Persicaria pensylvanica (Correll and Johnston, 1979. ps. 525). Splitters, again!! (Not to mention inconsistency.)
The example plants shown here were growing around a farm pond in the Ozark Highlands. Ottawa County, Oklahoma. October.
34. Dotted or water smartweed (Polygonum punctatum)- A widely though sporadically distributed smartweed or knotweed is the perennial species shown here growing in an old rock quarry in the Ozark Plateau. Dotted smartweed also grows far to the west of this location on the Southern High Plains by playas and other wetlands including springs. In some areas, especially where water seeps from hills or mountains springs are formed which in semiarid and arid regions are often known by the Spanish, scienega or cienaga. Such springs and seeps can form smaller playas. Similarly, drainage water from roads and irrigated fields sometimes forms manmade wetlands (at least temporarily) and these provide an environment for dotted smartweed.
This rhizomatous species is an excellent soil binder. Though not as widely distributed as some of the other Polygonum species, P. punctatum is a wetland range plant which often forms dense local colonies.
Newton County, Missouri. Late July, peak- bloom stage.
35. Flowering in a manmade wetland- Apex of sexual shoot (first slide) and inflorescence of dotted or water smartweed (or knotweed). Newton County, Missouri. Late July, peak- bloom stage.
I'm just about everywhere- Four composite or general views of a smartweed or knotweed known variously (and in various combinations) as pale smartweed, peachleaf knotweed, dockleaf knotweed, nodding smartweed, willow knotweed, and curlytop smartweed (Polygonum lapathifolium= Persicaria lapathifolia) growing on a drainage area in the northeastern edge of the Rolling Plains region of north Texas. This rank-growing annual is widely distributed with a species range that includes Eurasia as well as North America from Atlantic to Pacific Coasts. As such, peachleaf or dockleaf smartweed is an extremely variable species. For example, Fernald (1950, p. 583) described four varieties for P. lapathifolium found in northeastern North America. Pale smartweed generally grows in wet to damp habitats, especially those with disturbance (Correll and Johnston, 1979, p. 525; Great Plains Flora Association, 1986, ps. 226-227; Allred and Ivey, 2012, p. 481) such as the specimens shown here growing along an old ditch. In something of a contrast, Whitson et al. (1992, p. 511) stated that this "amphibious species" preferred of wet to moist "undisturbed sites".
Correll and Johnston (1979, p. 525) and Diggs et al. (1999, p. 902) regarded willow smartweed as most likely being an exotic weed introduced from Europe, but Whitson et al. (1992, p. 511) did not designate this weed as being an alien.
As is the case for all Polygonum species, P. lapathifolium provides fruit that is a valuable concentrate for wildlife. This is particularly so for birds, often waterfowl in the instance of this species (Haukos and Smith, 1997, p. 139).
Wichita County, Texas. Early October; peak standing crop, full-bloom phenological stage.
Foolproof shoots- Features of the shoot of willowleaf knotweed or pale smartweed shown at progressively closer camera distance and increasingly detailed views. The rust-brown to pale red pubescence in leaf axils is a dead giveaway for this Polygonum species. The Polygonum genus is a large and seemingly complex taxon that frequently has been divided into sections when some groups recognized as separate genera (eg. Persicaria, Tovara) by some authors have been included. Steyermark (1963, ps. 582-598) and Fernald (1950, ps. 572-588) followed such treatment.
Wichita County, Texas. Early October; peak standing crop, full-bloom phenological stage.
Namesake leaves- Leaves of Polygonum lapathifolium frequently designated as dockleaf or peachleaf smartweed or knotweed. A fast look at this specimen confirmed validity of the adjective of the common name. The prominent midrib (midvein) is a conspicuous feature of the leaves of willow smartweed.
Wichita County, Texas. Early October; peak standing crop, full-bloom phenological stage.
Curly tops- Flower cluster or inflorescence of peachleaf smartweed or pale knotweed with the typical "drooping" or "nodding" habit (Correll and Johnston, 1979, p. 525). This inflorescences is essentially a terminal, open (= having widely spaced branches) panicle with axillary racemes or spikelike racemes of numerous flowers.
Haukos and Smith (1997, p. 139) described this species as an important and characteristic forb of playas in the Great Plains, espeically the Southern Plains.
Wichita County, Texas. Early October; peak standing crop, full-bloom phenological stage.
36. Spikerush (Eleocharis montevidensis= E. arenicola)- This rhizomatous perennial is one of the more widespread of the Eleocharis species. It is regarded as the most common spikerush in Texas (Correll and Johnston, 1979, p. 276) and its geogrphical distribution extends from Oregon and Idaho into South America (Brazil to Argentina). Close attention to the specimen in the first of these two photographs revealed the rhizomatous feature of this species. This large clump actually consist of several smaller rhizome-originated clones or modules that "coalesced" into this apparent cespitose plant (one genetic individual or genet). Parts of two such modules were visible in the second photograph which presented more details of shoots.
This specimen was growing in a depression in an ephemeral drainage in the Grand Prairie of the Cross Timbers and Prairies area of northcentral Texas. Erath County, Texas. April, anthesis.
Shown below were several species of forbs (many of them weeds) that have been documented to grow on playas, including range vegetation on the perimeter of these grassland lakes. Source consulted (and recommended): Haukos and Smith (1997).
37. Great bulrush, softstem bulrush, or giant tule (S. validus= S. tabernaemontani). The example of this species was growing in a slough at edge of a tallgrass bottomland prairie just above Lost Creek in western portion of the Ozark Highlands (Mountains). According to Steyermark (1963) this species is the common bulrush of the Ozark Plateau. The terminal end of the culm that extended beyond the inflorescence in this specimen closely resenbled that of S. acutus, but this latter species does not occur in within 150 miles or more of this location (Steyermark, 1963, p. 292-293).
Ottawa County, Oklahoma. July, hard dough-grain stage.
38. Common bulrush (S. atrovirens)- This Scirpus species is probably the most common one in prairies of Missouri and eastern Kansas and Oklahoma. S. atrovirens is an extremely variable species. Steyermark (1963, p. 296) divided it into three varieties which Yatskievych (1999, ps. 429-432) elevated to three species. These plants were growing in a tallgrass prairie slough that drained into Lost Creek at the western edge of the Ozark Plateau.
Ottawa County, Oklahoma. June, hard dough-grain stage.
39. Prickly lettuce (Lactuca serriola)- Most of the native (and naturalized) Lactuca species are highly variable in morphology and in habitats. L. serriola is an annual Eurasian species that adapted to disturbed or partly bare areas including dry playas and margins of wet playas (Hukos and Smith, 1997, p. 47). This and other Lactuca species furnish outstanding greens when gathered at immature stages in the spring. Hillbilly spinish if you prefer. Deer and rabbits are also quite fond of Lactuca leaves.
There are two subfamilies of Compositae: 1) Tubuliflorae has some tubular flowers and the sap is watery and 2) Liguliflorae has all ligulate flowers and this sap is milky. Lactuca species are in the Liguliflorae. The composite inflorescence was described briefly in the immediately succeeding photo-caption.
The specimen presented here was growing in a moist hollow in the West Cross Timbers, Erath County, Texas, May, full-bloom phenological stage.
40. Inflorescence of annual sunflower (Helianthus annus)- The State Flower of the Jawhawker State of Kansas was domesticted as a major oil-seed field crop. This is mostly dwarf and hybrid varieties. The sunflower is of course a composite (family, Compositae or Asteraceae). The fruit of Helianthus species is an achene, "a dry, single-seeded, indehiscent fruit whose pericarp and seed coat are separate, except at the funiculus" (Smith, 1977). Achenes are borne on the head or capitulum which is made up of florets on the shaped (eg. cone) or flattened common receptacle called a disk. In many composite the disk and its disk (= tubular) flowers are surrounded or outlined by ray (ligulate) flowers forming a composite infloresence (hence, Compositae). Capitula are arranged in the pattern of a raceme, corymb, panicle, etc. (Smith, 1977, p. 214). Surrounding the capitulae are involucres of bracts each bract of which is a phyllary. All-in-all a complex floral arrangement.
Helianthus species are in the Tubuliflorae subfamily mentioned in the preceding photo-caption. Sunflowers are members of the large tribe, Heliantheae.
Heads of sunflower characteristically face in direction of the sun in daylight hours (phenomenon of nutation) which is obviously origin of both common and genus name. (Heloianthus comes from the Latin and Greek helio in reference to the sun, solar, or a rising star while anthos is Greek for a flower).
Annual sunflower is typically a range plant of disturbed ground (as would be expected of many, or most, annual forbs) though it is not necessarily a pioneer species. Bare soil of playas is thus often "prime real estate" for annual sunflower. Unlike some of the perennial sunflowers such as Maximilian sunflower (H. maximiliani), Jerusalem artichoke (H. tuberosus), or ashy or gray sunflower (H. mollis) the shoots of H. annus are not particularily palatable to grazing animals. The fruits are a different story as anyone who fills winter bird-feeders can attest. Annual sunflower is one of the better species for upland game bird fed-plots. Presence of annual sunflower around playas is a blessing from standpoint of wildlife habitat.
Erath County, Texas. July, full-bloom stage.
41. Uprooted annual sunflower- This small taproot and taproot system of annual sunflower was typical of an annual range forb.This also shoed the basal part and shoot branching pattern of this species.
Erath County, Texas. July, early bloom stage.
42. Common cocklebur (Xanthium saccharatum)- Xanthium species are also members of the large Heliantheae (tribe) as are Helianthus spp. There are two Xanthium species in Texas, the home state of the specimen introduced here: 1) X. spinosum and X strumarium. X spinosum has a spine near base of its leaves (by abscision layer); X strumarium lacks the basal spine. This plant was X. strumarium.
Cockleburrs are annual composites, and all Xanthium species are monoecious. The phyllaries (see again the first photo-caption for annual sunflower) of the pistillate capitulae are united into an involcure called a "burr" (or "bur"). There are two pistillate flowers within each bur so there are typically two fruits (achenes) per bur (two seeds per bur in farmer parlence).
Erath County, Texas. September, immature fruit phenological stage.
43. Burr of cocklebur- Fully mature (ripe) involucre of cocklebur. The hardened involucre (of the phyllaries) surrounds two female flowers, hence there are two achenes (fruit type of Compositae) per bur at maturity.
Cockleburrs are another of numerous poisonous range plants. Important references included: Kingsbury (1964, ps. 17, 258, 440-443), Sperry et al. (1964, 47-48), Cheeke and Shull (1985, p. 212-214), Fuller and McClintock (1986, ps. 7, 99-1005), Burrows and Tyrl (2001, ps.214-218), and Hart et al. (2003, 224-225). Cockleburpoisoning occurs when cocklebur seedlings are eaten. Cocklebur sprouting takes place when inundated soil has dried out sufficiently. This condition exist on wet soil along shores of streams, ponds, and other bodies of water including, of course, playa lakes. According to Burrows and Tyrl (2991, ps. 215-217) the poisonous principle (= toxin) is any of a series of diterpene glycosides that induces a number of metabolic disorders, including inhibition of oxidative phosphorylation and ATP formation, and causes poisoning symptoms such as weakness, ataxia, vomiting, and seizures along with a decrease in blood glucose and liver necrosis. Cocklebur toxicity is almost always fatal. All livestock species have been reported to be susceptible. Swine are especially apt to be poisoned. Could this be a biological control of feral range hogs? Wishful thinking.
Involucres also cause mechanical to grazing animals, and especially to clueless humans who, when hand-milking cows, forget to catch Bossy's tail behind their knee joint and are slapped up-side the head with a bovine twitch loaded with cockleburs. One of the first lessons your Okie farmboy author learned in dealing with others was to avoid the mace of a cockle-burred cow tail. (It was a lesson that helped prepare him for dealing with university administrators who are much less useful, intelligent, and well-behaved than any high-headed Jersey-- and of about as much value as a cocklebur.)
Erath County, Texas. November.
44. Curlycup gumweed (Grindelia squarrosa)- Stand of curly gumweed. This species has a sticky exudate on leaves, capitulum, and frequently even stem which explains "gumweed". Also it was reported that American Indians and frontiersmen chewed apionerThis composite is in the Tubluiflorae as a member of the aster tribe, Astereae. Curlycup gumweed has traditionally been classified as an increaser in response to grazing and rated as having fair forage value. Curlycup gumweed has been reported to be a secondary or facultative accumulator of selenium (Kingsbury, 1964, p. 406; Burrows and Tyrl, 2002, p.529). Obviously potential selenium toxicity would only be a problem on seleniferous soils.
Curlycup gumweed often grows as isolated individual plants, but sometimes this species forms dense populations as in this "low spot" in the Grand Paririe of northcentral Texas.Erath County, Texas. September, late estival aspect and full-bloom phenological stage.
45. Curlycup gumweed- Two photographs displayed specific features of this member of the aster tribe (Astereae) of Compositae. Tarleton State University Hunewell Ranch, Erath County, Texas. September, full-bloom stage.
46. Horseweed or mare's tail (Conyza canadensis= Eriegeron ccnadensis)- Mare's tail is one of the most common of all pioneer species on old-fields (= go-back land) in areas where this species is adapted. In fact, it is the textbook example of such a pioneer species of formely tilled land. C. canadensis is typically the dominant plant of an abandoned farm field in the first warm-season growing period. Horseweed often reamins the dominant plant for the first three to five years following abandonment of a farm field (or devasted land like a strip coal mine) in most locations over the vast region from the Atlanic Coast to the central prairies region from the Prairie Provinces to Mexico
The bare soil of a dry or drying playa bed and around the perimeter of a playa lake is an edaphic environment similar to that of an old-field. Such abiotic environments are ideal habitat for mare's tail. It was strongly stressed at this point that under such conditions mare's tail or horseweed is not a weed. C. canadesnsis is a weed when (as long as) the land is being used for field crops or related agricultural uses, but when land that was abandoned for field cropping purposes is being allowed to "go-back" (revert) to rangeland or forest by secondary plant successionn C. candensis sis one of the most valuable of all plants. In secondary succession pioneer plants, of which horseweed is one of the sterotypic examples, provide many ecosystems functions (eg. adding organic matter, protecting soil from erosion, increaseing water infiltration, recycling nutrients) that prepare the land for the next seral stage of vegetation. This is the process of succession that in the classis Clementsian model was known as reaction. In more recent parlance the process has been called facilitation.
Seral stages (successional plant communities below or prior to climax) are often ideal for certain wildlife species, especially those classified as r-selected species. The concept of r-selection refers to natural adaptation of species and resource allocations in the life cycle of these species such that the intrinsic rate of increase is maximized (optimized is propbaly more precise) in order that the species can rapidly colonize available favorable habitats. In this conceptual view r-selected species are opportunistic species that through natural selection have the ability to respond to rapidly changing environments. Fugitive species is a synonym for opportunistic species. Both of these synonymous terms refer to species that are characteristic of newly created habitats (eg. plowed ground, fresh sand bars, road-cuts, mined land, forest clearcuts) that are often relatively harsh, periodically disturbed, and generally unstable. Fugitive (= r-selected) species are relatively small, short-lived (among plants, annuals or ephemerals), and have shorter genertion intervals (ie. early sexual maturity). In plants, r-selected species have lower root:shoot ratios; that is, they have relatively more biomass in aboveground parts.
In context of succession, r-selected species are generally seral while K-selected species tend to be climax or equilibrium species (vs. fugitive species). K-selected plant species are typically perennnials with high root-shoot ratios such they are compeititive for more limited resources (in contrast to the pulse of available resources like space, light, or newly available soil nutrients under habitat conditions that favor r-selection). In the process of succession, plant and animal species of r-selection and K-selection (again, K-selected species are called equilibrium species) develop "hand-in-glove so as to form communities along the sere, the path of succession, (ie. seral stages until the climax community olr state is reached). In other words organisms of similar successional status occur together and form r- and K-selected communities or seral stages and, finally, the climax state.
Among animals, bobwhite quail (Colinus virginianus) are an r-selected species. Northern bobwhite abound in certain seral stages including the pioneer plant seres of old-fields or go-back land. Horseweed is a a major pioneer plant and a textbook r-selected species. Northern bobwhite probably use horseweed primarily for cover. Sparse foliage of lower shoots of horseweed enable bobwhite to "bust out" quickly. All lovers of the covey rise should be lovers of horseweed or mare's tail, and all "bird hunters" should be students of succession and plant life cycles.
Horseweed or mare's tail is another composite of the aster tribe.
47. R-selected and top-heavy- Two robust individuals of horseweed or mare's tail growing on a severely disturbed local area in West Cross Timbers. First photograph presented entire shoot portions of plants; second photograph was of the two plants' inflorescences. Here were shown two key features of r-selected plant species: 1) large biomass of shoot relative to root (greater shoot : root ratio) and 2) extremely large flowering portions of shoot (relatively rich allocation of resources by plants to sexual reproduction as shown by immense panicle of many composite flowers).
These individuals had pioneered a severely disturbed habitat (a recent construction location).
Erath County, Texas. November.
48. Inflorescence of mare's tail or horseweed- Flower cluster was bearing fruit (achene) and at the hard-seed stage and not a flowering stage of phenology. Disturbed fencerow, Erath County, Texas. September.
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49. Details of inflorescence of horseweed or mare's tail- First slide was of several individual secondary branches arising from primary branches of a large inflorescence of Conyza canadensis= Eriegeron ccnadensis on one of the large plants introduced in the set of two slides immediately above the preceding slide. Second slide presented detail of one secondary branch of this horseweed plant.
Incidentally the common name of horseweed was derived from the fact.that leaves and flowers release compounds (terpenes have been the major chemicals implicated) that frequently cause respiratory irritation in horses (Whitson et al., 1992, p. 123;), but for unknown reasons (Burrows and Tyrl, 2001, ps. 226-227) did not mention this commonly reported phenomenon. Basis for the common name of mare's tail was obvious (except to jackasses).
Erath County, Texas (recent local disturbance habitat caused by a construction project). Novermber, phenological stages ranged from late-bloom to soft-dough of fruit.
50. Redroot pigweed (Amaranthus retroflexus)- Many of the amaranths are valuable food crops in certain parts of the world, especially Central and South America. Adult plants of A. retroflexus and A. spinosus can be valuable forage plants. As a boy this author pulled weeds of both these species from the home "tater patch" and fed them to hogs-- to the hogs' delight and with no ill-effects. Beginners luck perhaps. Amaranthus species have several ways to poison animals including both nitrate and oxalate accumulation as well as perirenal edema and death due to this renal disease. A. retroflexus is the most common toxic species. Toxicity due to nitrate accumulation and nitrite toxicity can be very rapid with death in ruminant sometimes measured in minutes (Burrows and Tyrl, 2001, ps. 23-27). Other references included Kingsbury (164, p. 244-245), Cheeke and Shull (1985, p. 314, 318, 368-369), Fuller and McClintock (1986, p. 384), and Hart et al. (2003, ps. 30-31).
Redroot pigweed is one of several Amaranthus species known in some locales as "careless weed". This always struck this author as rather ridiculous given that there is nothing careless about the way these species survive. Pigweed (= careless) weed species are, however, examples of r-selected species like horseweed just discussed. Many of the characteristics of r-selected species such as prodigenous sexual reproduction and high-density populations might fit the meaning of "careless" to provide yet another example of the astute observtion and insight of conventional wisdom.
The examples shown here were growing in a depression, the back furrow, of plowed ground. Erath County, Texas.
51. Curly, sour, or yellow dock (Rumex crispus)- This Eurasian noxious plant has a large taproot system and is a weed of cultivated lands as well as range. Of most interest on range is the situation that curly dock (as well as some other Rumex spp.) is a poisonous plant. The poisonous principle has generally been regarded as soluble oxalates. Rumex species are not generally palatable and therefore pose no threat to livestock under most conditions. Dayton (1960, p. 83) described forage value of curly dock varying "from worthless to fair or fairly good for sheep and cattle".
Interestingly this species is often used as a source of "wild" spring greens by hillbillies (including the author). Other species used as a pot herb and often in association with dock include pokeweed (Phytolaca america), various wild lettuces (Lactuca spp., including L. serriola shown above), sow thistle (Sonchus spp), dandelion (Taraxacum officale), and, though often later in the season, lamb's quarters (Chenopodium album). In this regard it was noted that a fellow hillbilly but also outstanding plant taxonomist Steyrermark (1963, ps. 580, 612, 630, 1635, 1636, 1638) noted the same culinary delights. References dealing with toxic propreties of Rumex crispus included Kingsbury (1964, 231-233), Burrows and Tyrl (2001, ps. 984-987), and Hart et al. (2003, ps. 172-173).
The specimen presented here was growing on a bottomland site (a floodplain) in the middle of a dense stand of Canada wildrye in the Grand Prairie of northcentral Texas. Erath County, Texas.
52. Silverleaf nightshade (Solanum eleagnifolium)- Still yet another poisonous range plant. Most species of the Solonaceae, the nightshade family, should be regarded as having the potential of being toxic under certain conditions. Toxic compounds are akaloids. These include solanine of green tubers of potato (S. tuberosum) and tomatidine in immature fruits of tomato (Lycopersicon esculentum= Solanum lycopersicum). Livestock and humans have been poisoned from eating the "vines" , tubers, and fruit of these domestic crops.
Silverleaf nightshade is generally not palatable, but all parts of the plant can be toxic if consumed in adequate quantities. S. eleagnifolium is the species that has caused most poisoning on the Western Range. Cattle are most susceptible with sheep having more tolerance and goats having most tolerance to the alkaloid. Same standard references include Kingsbury (1964, p. 290),. Cheeke and Shull (1985, p. 135), Burrows and Tyrl (2001, ps. 1127-1136), and Hart et al. (2003, 206-207).
Erath County, Texas. September, full-bloom and immature fruit phenology.
53. Narrowleaf cattail (Typha angustifolia) and American bulrush (Scirpus americanus) marsh surrounded by squirrel bottlebrush and inland saltgrass, which in turn is surrounded by a zone comprised of sideoats grama and little bluestem. Historic Bents Fort to far right, Otero County, Colorado. July.FRES No. 41 (Wet Grasslands Ecosystem). K-42 (Tule Marsh) in middle of K-62 (Bluestem-Gramagrass Prairie). No SRM listing for this cover type (or for any prairie marsh type). Southwestern Tablelands- Piedmont Plains and Tablelands Ecoregion, 26e (Chapman et al., 2006).
54. The cat and her tail- Narrowleaf cattail in peak bloom showing the pistillate infloresceence, "cat" (below) and staminate inflorescence, "cat tail" (above).
Otero County, Colorado. Late June; anthesis.
55. "Nervous as a cat in a room full of rocking chairs"- Close-up view of the inflorescence of the narrowleaf cattail presented in the immediately preceding slide. Emphasis was on the "cat tail" portion, the male inflorescence (or male portion of the inflorescence) shown in its full length above a small part of the upper portion of the "cat", the female part of the flower cluster or the pistillate inflorescence (depending on interpretation). Typha species are interpreted as monoecious so that there are separate male and female inflorescences even though they adjoin each other on the same stalk. Smith (1977, p. 239) described this arrangement as "a tightly compacted terminal spadix". Now ain't that the cat's whiskers (or something else)?
Otero County, Colorado. Late June; anthesis.
Shown below were three photographs of former fields (row crops and small grains) on highly erodible land that had been successfully reseeded to mixtures of native grasses. These three examples were on the Great Plains physiographic province. The first two slides were from the High Plains (part of the central Great Plains) and the third slide was from the Colorado Piedmont. Both of these are sections or sub-provinces of the Great Plains.
**Note: students in Range Management and Forestry should familarize themselves with the concept of physiographic provinces and study the literature of the provinces in which the ranges and forests with which they work occur. The classic or “bible” for physiography of the “lower 48 states” remains Fenneman (1931, 1938). A more recent, but less detailed, treatment for North America north of Mexico is Hunt (1974). An excellent treatment of the Great Plains specifically is Trimble (1990).
Reseeding range (and replanting forests) is a form of, and a practice within, the category of conservation known as restoration. Conservation is scientific management of natural resources by shifting the rate of resource use to the future. It is a general concept and differs in application and outcome of use between renewable and nonrenewable natural resources. Restoration is that stage of conservation in which there is nonuse combined with some intensity of inputs added back to the natural resource(s) for purposes of replenishing or rebuilding the resoure(s) so that it can again sustain use. Restoration is the lowest rate of resource use in the array of conservation, the lowest stage in the range in rates or levels of resource use. Depletion or exhaustion is the final level or last rate of resource use because the natural resource is either used up, if nonrenewable resources, or exterminated (driven extinct) if a renewable resource such as a species of organism. Exhaustion is nonuse as is restoration, but exhastion is nonuse because the resource formerly received the greatest total use relative to the rates that could sustain use. Using natural resources at rates higher or greater than that (those) which can sustain use (ie. exceeding sustained yield) is the stage known as exploitation. Nonrenewable resources cannot sustain use. That is why they are nonrenewable. Depletion, the result of exploitation, does not have to be total physical or biological elimination (extinction of species most certainly is of course), but it may be economic depletion (ie. the resource becomes so scarce that it cost more to harvest or extract it than it is worth in the prevailing market).
Restoration is that level of scientific management or conservation (= wise use of resources to shift use farther into the future) that attempts to correct the abuses of exploitation which ended in the state of depletion. The goal of restoration is to “bring back”, to replenish, the depleted natural resource(s) so as to be able to use them again at some point in the future. They should then be used at rates that can sustain use (at rates of use consistent with sustained yield). This is the stage in the array of natural resource use known as conservation.
Restoration in this context and strict definition should not be confused with the specific meaning of restoration as that level of reclamation of drastically altered (= drastically disturbed, radically modified, devastated, derelict) lands or ecosystems in which everything is completely returned to the pre-disturbance (prior to the severe perturbation) state. Restoration in that context refers specifically to lands (or waters) disturbed by human actions like mines, quarries, oil fields, abandoned roads, bombing ranges, chanalized rivers, land fills, chemical dumps, etc. The general idea of “land repair” or replenishing of natural resources is consistent with both of these specific uses of restoration.
Restoration is reinvestment in natural resources just as exhaustion was disinvestment in resources (ie. we ate the “seed wheat” and now we must buy more seed to be able to plant wheat if we are to have wheat to eat, and sow, in the future). Examples of natural resource restoration include closed seasons (no open hunting or fishing season) for rare and endangered species, preservation (rates of resource use less than those of conservation) of relict vegetation, and park management for irreplaceable or priceless natural wonders like unique scenery.
Restoration management or inputs in Range Management and Forestry include reseeding grasses and forbs, replanting woody plants, noxious plant control (reduction in cover, density, etc. of weeds and brush which are ecological invaders of the climax or desired plant community), soil and water conservation structures, fertilization, etc. These are known generally as improvement practices. Range improvement generally and usually means restoration of ranges depleted by overgrazing, under- or overburning, farming, commercial activities, and so forth. Improvement practices such as those just listed aid or increase the rate of range recovery by facilitating the processes of secondary succession. Man gives a boost to Mother Nature to help make amends for his past abuse of natural resources (such as mismanagement of range or forest). Improvement practices differ from developments or development practices such as road and trail construction, water development, fencing, etc. The latter are not restoration practices, but rather management and physical things that facilitate the overall effective use and improve the efficiency— especially the economic efficiency —of use of the resources (including human, financial, and knowledge resources as well as natural resources).
Range reseeding is one of the major categories of range improvement practices (restoration management). The next three slides were chosen as examples of range reseeding that were done under the United States Department of Agriculture Conservation Reserve Program. The Conservation Reserve Program (CRP) was passed in 1985 in response to the fencerow-to-fencerow grain and row crop farming during a relatively brief period during the 1970s (Dr. Earl Butz was Secretary of Agriculture in the Nixon Administration) when the Soviet Union was buying feedstuffs from the USA to build up its livestock and poultry feeding industries. It appeared that the USSR would be buying feed grains and oil seeds from the United States for the proverbial “foreseeable future”. US farmers took a page from the past (or actually failed to read past history correctly) and plowed out fragile grasslands that had been marginal for field crop production under all but the economies of World Wars I and II. The almost immediate result over much of the Great Plains was dust storms that at local community levels were almost on par with those of the 1930s (thought not nearly as widespread as during the infamous Dust Bowl years). There were similar problems with water-caused soil erosion over much of the Midwest. There was concurrent draining of wetlands that were also marginal (sub-marginal actually) for cropland other than in the seemingly good times or happy days of unimaginable market demand for many field crop commodities such as wheat, oil seeds, and feed grains (most notably corn).
As immediate as the farmers fencerow-to-fencerow response was the “hue and cry” from a broad spectrum of concerned citizens that spanned the political spectrum of both major US political parties and from conservatives to welfare liberals. Only some of the most diehard free market libertarians (and those who stood to gain from grain deals) failed to see the classic market failure or negative externality (adverse spillover effects) of this short-term response to what was destined to be a short-lived boom market. Of course many elected and appointed politicians from Farm Belt States elected to keep silent as long as they could (at least up to time of re-election), but there was clearly a groundswell grassroots movement to halt the farming of highly erosion-prone land. All this was to the technically correct war cry of “Dust Bowl”.
Meanwhile the Soviet dictators sensed the weakened power of the US Presidency in the post-Viet Nam, post-Watergate era and the naivette of President Jimmy Carter. Thereupon the USSR invaded neighboring Afghanistan fairly early in the Carter Administration. President Jimmy’s dumbstruck response was an ill-fated and totally ineffective embargo (ban on shipping and/or selling) of American-grown grains to the big bad Russian bear. Like the market-sensitive and ever-optomistic farmers, President Carter failed to correctly interpret history. An executive-ordered embargo (a presidential-invoked prohibition of trade in commodities and/or in departure or entry of commercial ships at US ports) on overseas shipping of commodities that an elected official arbitrarily deems “contraband” will always fail without a naval blockade. The grain US farmers could not sell to the Soviets was sold and shipped by American allies like Canada, Australia, and Argentina. The Carter Administrtion did not have the force of international law (the legal standing), political clot, or the “guts” to blow out of the water Canadian, Australian, and Argentine ships loaded with the kinds of feedstuffs American growers could not sell. The only losers in this fiasco were American farmers, and the reputation of the United States of American as a reliable source or supplier of agricultural products.
The Carter boondoogle over the sales ban on American grain exposed the fencerow-to-fencerow farming and “breaking out” of highly erodable land for what it was: a pact with the Devil in which the US sold its conservation soul and still never had the stones turned into promished bread. This “sad state of affairs” was coupled with that of the now over-extended farmers who had been loaned vast credit for expansion (purchase of more land at inflated prices and expensive farming equipment) based on the inflated value of their farmland (built on the anticipation of increased sales of grain, oil seeds, etc.). By the time Ronald Reagan was elected President the stage was set for the worst farm crisis since the Great Depression. Agri-businesses, banks, and many local retailers in farming communities faced dire financial times. Many went broke. Some farmers committed suicide.
The stage was set for Federal action. Congress acted (in its own due time) with passage of the Food Security Act of 1985. Title XII of this legislation established the Conservation Reserve Program. The CRP would pay farmers to 1) idle or “retire” highly erodable land and 2) seed these acres back to permanent vegetation like native or introduced perennial grasses or, in some cases, trees. The 1985 CRP provision became known as the “sod-buster bill”. Farmers made bids for their land to go into CRP and if their bids were accepted they could enter into a contract with Uncle Sam to keep their erosion-prone land in species that were approved by the USDA (Soil Conservation Service) officials. The maximum period of this “lease to Uncle Sam” (retirement of highly erodible land from field crop production) was 10 years. “Then what?” remains the over-riding question. The 1990 farm bill expanded the CRP concept to wetlands, the so-called “swamp-buster bill”.
Administration of CRP was largely at the county level and the total amound of land retired under the Conservation Reserve Program was limited to 25% of the cropland in any given county unless it was shown by standards of the program that there would be no adverse economic impacts on the local economy in which case withdrawl for CRP leases was limited to 30% of the cropland in the county. The CRP was reduced somewhat by the 1996 farm bill, and the question of permanence of retirement of highly erodible land remained unresolved.
Conservation Reserve was an older term going back at least to the USDA Soil Bank program initiated in 1956. In all such cases, the stated reason for retiring highly erodible land was soil conservation. Another (and, probably, the major) reason was to reduce crop surpluses and, thereby, crop support payments. Idlying acres was of more immediate concern as a way to reduce costs to US taxpayers, and use tax dollars where congressmen got more votes for their allocations, than as a way to conserve soil and water. This major—though understated—objective was not totally effective because highly erodible land is by its nature marginal land for field crop production and often, after idlying their marginal fields, producers managed the remaining land more intensively and “made up the difference”.
The CRP was very effective in getting land back into permanent perennial vegetation (much of this as range or as introduced species that would persist as if they were native). These CRP lands demonstrated two basic lessons: 1) range managers, agronomists, foresters, etc. have developed the technology to revegetate abandoned farmland and 2) land (and water)-owners will respond to economic incentives and adopt conservation practices if “the price is right”. It was certainly to their credit that most farmers supported CRP (afterall they were being paid as much, if not more, than these marginal lands would return as farm fields).
The Conservation Reserve Program was and remains (probably always will remain) controversial. It was just stated that the CRP was, beyond any doubt, an incentive to farmers to idle highly erodible land and replant that land to permanent vegetation that protects it against the ravages of soil erosion.
The CRP (and earlier programs like the Soil Band) was also, however, a clear incentive to farmers to plow out these highly erodible lands in the first place. Farmers could reasonably bet from past history that eventually the US government (and possible some state governments as well) would pay them to put these highly erosion-susceptable acres back into “grass”, land which was marginal for crop production and which should never have plowed under (or drained) to begin with. Meanwhile what about the faithful stewards of the land? What reward, what incentive, was returned to those landowners who cherished their “grass” (native vegetation, or reseeded ranges and permanent agronomic pastures some of which had been established in the first round of conservation plantings after the folly of “sod-busting” had been recognized)? They got nothing, absolutely nothing. Zero. Actually they did get something: competition for their commodities in the market place from the poor stewards who, like Essau, had despised their birthright. Wise land managers had to compete on the open market with those of their fellow producers who had plowed-out their erodible acres and got paid a bonus for such inefficient management and immoral poor stewardship! The farmer who was an unfit steward of his highly erodible land was given a reward for his failed stewardship. Worse yet, this gave him an advantage over the faithful steward who got no financial renumeration and instead had to compete with what by definition was an economically inefficient producer, the very one who did not manage his resources wisely or morally.
Such goings-on clearly constitute market failure. Where is the social justice, equity, or fairness in such a policy as this? The CRP made the playing field of the market place less level. It sloped the ground of the open market in favor of producers who “broke the rules” and thereby penalized producers who “played by the rules” and who were more economically efficient (as was self-evident by the fact that they did not require a “bail-out” via conservation payments) .
The CRP was a “success story” to those whose main, or only, concern was stopping soil erosion (and providing other conservation benefits like wildlife habitat, clean air, less mining of ground water for irrigation) or who viewed CRP as a bargain because federal renting or leasing of CRP land was less expensive to the taxpayer than continuing to pay price supports. Certainly all “real rangemen” would agree that any reason (or excuse) to put non-arable land— maybe any land for that matter— back into range and negate sod-busting was acceptable to that end. It cannot be denied though that programs like Soil Bank and CRP amounted to subsidies to the economically inefficient producer (and unfaithful steward) while offering unfair competition for the more efficient manager and faithful steward of natural resources.
Finally the big question remains: How long will these landowners who tried to farm sub-marginal land – and were paid a subsidy to do so— keep the land in the CRP. Is there anything to prevent a repeat performance of pay and plow out, pay and plow out, ad infinitum? How can taxpayers be assured that their reinvestment in natural resources— resources for which which they have no property rights — will be a rational investment and not some environmental Enron? What reasonable expectation can those who pay the way for conservation be reasonable assured that programs like the CRP are in final analysis “wise use” of their resources?
In the author’s opinion the Conservation Reserve Program was beneficial overall. Net results of conserving land and related natural resources was worth the cost, but it was marginal. The program had more right than wrong with it, but it is unfair and, ultimately, it will be a flawed and failed approach. There has to be a better way. Maybe some young reader will come up with it.
The Society for Range Managemeant passed a policy statement and a resolution regarding the Conservation Reserve Program which read in part: “… the Society advocates that productive, sustainable, economically and ecologically sound management systems be developed and applied on all CRP lands. This should be accomplished by keeping highly erodible lands in permanent vegetative cover” (The Trail Boss News, October 2001).
56. Reseeded mixed prairie- Abandoned cropland reseeded to native tallgrass and midgrass (and, perhaps, even shortgrass) species under the federal Conservation Reserve Program. To conform to conservation compliance within terms of the USDA price support system the owner-operator of this farmland entered into a contract with the United States whereby these highly erodable acres were taken out of row crop and small grains production and restored to a grassland community closely resembling the pre-Columiban or climax mixed prairie grassland. This three-year-old seeding in the beauty of it’s fall foliage included plants of the following native grasses (not in any general order of species composition): little bluestem, sand bluestem, sand lovegrass, Indiangrass, and sideoats grama.
FRES No. 38 (Plains Grasslands Ecosystem), K-60 (Wheatgrass-Bluestem-Needlegrass ) and edge of K-62 (Bluestem-Grama Prairie) were potential natural vegetation mapping units, but this was reseeded was more of K-67 (Nebraska Sandhills Prairie) or a “duke’s mixture” of these adjoining Kuchler units. SRM and range site designations were even less precise (hence, relevant) than larger-scale units of vegetation. This was in the Loess Hills and Dissected Plains area of southwestern Nebraska. Weaver and Alberston (1956, ps. 193-197) provided an apt description of the native grassland vegetation. Hays County, Nebraska. October (autumnal aspect).
57. Reseeded mixed prairie- Former cropland on highly erodable acres was reseeded under a Conservation Reserve Program contract to a “real mixture” of native grass species which resulted in grassland restoration to the point of a reconstructed mixed prairie. The dominant species in this mixture as it appeared at time of photograph was sideoats grama. Other grass species found in the reseeded prairie (and presumedly included in the seeding mixture) included plains lovegrass, sand bluestem, and blue grama. Both white and yellow sweet clover were common, but were probably volunteer species. (Melilots [from Melilotus spp.] were common in disturbed areas such as all along highway rights-of-way in this area and they have naturalized over much of the central part of North America, especially the Great Plains.)
The author recalled vividly driving in a blinding dust storm across this exact location in March 1975, 23 years before he took this photograph. Wind-eroded soil had blown half-way across one lane of the paved highway over lengthy stretches so that motorists were restricted to a single lane. This was of no consequence for travel across this sparsely populated remote area, but the damage to the land and the lives of local people was monumental. Wind-erosion in this southwestern corner of Colorado and adjoining parts of Texas, New Mexico, Oklahoma, and Kansas was one of the most serious problems and major areas of concern that led to passage of the Conservation Reserve Progaram in 1985. Current “black blizzards” and “rolling dusters” such as the one impressed indelibly on the author’s mind were frequently used as examples to prove that such catastrophes and failures of stewardship were immediately pressing serious problems. Such tragedies proved that soil erosion was not just a distant part of history from the “dirty thirties” when Hugh Hammond Bennett evangelized for soil conservation or a Hollywood backdrop for the oppression portrayed in The Grapes of Wrath. It was, however, the right way to end a moralizing picture show when the author took this slide of restored mixed prairie on land that almost a quarter century earlier was blowing away.
FRES No. 38 (Plains Grassland Ecosystem), K-58 (Grama-Buffalo Grass), SRM would vary locally among 704, 706,and 715, the latter being the regional climax as mapped by Kuchler. Baca County, Colorado. July.
58. Former irrigated cropland reseeded back to native mixed prairie- The city of Aurora, Colorado was facing dire water shortages as it experienced rapid growth. Aurora did not have water rights sufficient to sustain it’s unsatiable appetite for water. Aurora had to purchase water in the form of water rights in order to survive (at least at the standard of living to which it was accustomed). Aurora had no alternative but to buy the water rights of water-owners, primarily irrigation farmers. For the uninitiated and greenhorns like those from “the East” a short but instructive digression into water law was in order. NOTE: water law is a highly specialized and legally technical body of jurisprudence. In fact it is one of the most technical with many nuances and intricacies. The following thumbnail sketch was offered as an introduction to water law as it pertains to use and ownership of water in agricultural production. This brief description was drawn from the authors nonlegal background and as adopted from general texts especially Barlowe (1986, ps. 344-351).
There are two fundamental legal doctrines of water rights in the United States. The older one which traces back long before English law is the riparian doctrine. Common-law riparian doctrine says in effect that all landowners whose land has or borders on a stream or natural body of water has a property right to a flow of water undiminished in quantity and quality except as may be diminished or changed by upper stream riparian owners solely for domestic purposes and for the watering of livestock. This form of water rights generally holds in all states of the Union except for all or parts of the seventeen western states (often termed the “western range states”). The other basic doctrine of water rights— in total or in some modified form —in all or parts of the seventeen western (the plains, mountains, and Pacific) states is the appropriation (= prior-appropriateion) doctrine, also often known as the Colorado Doctrine after the state that first prescribed it in its state constitution upon admission to the Union.
The prior-appropriateion doctrine asserts that both landowners with riparian water and landowners without riparian water on their property are free to appropriate by legal process water from streams (and acquifiers) for its beneficial use (not restricted to domestic or household and livestock uses). In net effect, this grants freedom under law to divert water that is not on one’s own land to one’s land for beneficial use. The diverted water then becomes legal property the same as for land, assuming legal procedure was followed in acquiring the property right in water. This separates land ownership from water ownership. The property owner who “got there first” and legally laid claim to water not on his own land became the legal owner of the water that might well be on land later legally owned (claimed, bought, inherited, etc.) by another. In such case the landowner who adquired the property rights to the land after the water rights were already established does not legally own the water that is on his legally owned land, at least not that part of the water claimed by the waterowner who legally acquired the right to that water by prior beneficial use. Water rights and land rights are completely separate just as in the case where mineral rights on a parcel of land are separate from the rights accruing to land ownership (ie. a land buyer may or may not get water rights or mineral rights). With prior appropriation, water (water rights) can be sold as a real estate commodity the same as land. Obviously in arid and even semiarid regions the water rights become all powerful in determining the value of land (ie. what the land is really worth for certain purposes, what the true worth of land ownership is, of what value land rights are). This applies at the level of states as when Kansas and Colorado “go to war over water rights”all the way to the US Supreme Court. It even holds force in water law among nations entering into international treaties or contracts (eg. between the United States and the Republic of Mexico regarding water in rivers like the Colorado and the Rio Grande).
Technically the so-called “plains states” (the tier of states from Texas through North Dakota) legally apply a modified form of the appropriation (prior appropriation in conjuction with parts of the riparian doctrine). As California was the first state to adopt this modified riparian doctrine it is often known as the California Doctrine.
The reseeded grassland shown here was a field formerly under irrigation for prodution of various crops like the famous Rocky Ford cantaloupe (Cucumis melo var. cantalupensis), onion (Allium cepa), alfalfa (Medicago sativa), and sugar beets (Beta vularis). The waterowner also owned the land, but after he he sold his water rights (a commodity in states enforcing the appropriation and modified version of appropriation doctrine) the land became useless for the field crops best adapted to the climate, soils, markets, etc. of this area. The owner who now owns only the land (the landowner who sold his property in water, the water rights) concluded that dry land agriculture was not an option for him. Thereupon he enrolled his land in the Conservation Reserve Program. (What pressure, if any, from municipalities, government agencies, family members, neighbors, etc. may have dissuaded the landowner from continuing to farm this field was unknown to the author.) The lesson was that without irrigation water this former cropland was deemed no longer arable and put back in range. HURRAY! This was an example of how sociopoliticoeconomic factors help determine the use made of land (and water). Like the Conservation Reserve Program, this private example was an illustration of how social-cultural factors can override physical-chemical and biological factors in dictating both personal decisions and public policy regarding land and water use.
The reseeding mixture included alkali sacaton, sideoats grama, blue grama, switchgrass, and western wheatgrass, all of which were well-represented in the grassland community shown here. In addition there was an abundance of volunteer sand dropseed (Sporobolus cryptandrus), probably the most common grass in this part of the Great Plains.
FRES No. (Plains Grassland Ecosystem), K-58 (Grama-Buffalo Grass), SRM variant of 725. Reseeded to a locally adapted mixture resembling a mixed prairie of tall-, mid-, and shortgrass species. Crowley County, Colorado. July.
59. Emergency grazing of CRP land- During the extreme drought of 2002 landowners were allowed to graze land enrolled in the Conservation Reserve Program. It is in drought, the great risk in ranching, that the real value of forage produced under this program becomes most evident. It also proves the value of always managing so as to have some reserve source of feed. The alternatives of bankruptcy and liquidation are less appealing. No, this herbage with large amounts of rank, leached dry matter from several previous growing seasons, is far from quality feed, but it beats "holler belly" and dust.
Lincoln County, Colorado. June.
60. Clean farming= sad, sick scene- "Clean farming" is the term applied to tillage of farmland with little or, at least, inadequate crop residue on the soil surface resulting in soil erosion. Accelerated soil loss is particularily likly on highly erodible land. An example of this state of improper farming was shown here as it occured on cropland in the Central High Plains of northeastern Colorado. Excessive runoff (overland flow) from this clean-tilled field carried irreplacable (in human time frame) soil through a "tin horn (corrugated steel culvert) to the other side of the highway where the sediment was deposited on mixed prairie to depths that covered and killed native grasses. This was an early stage of gully formation. On the upslope land behind the gully channel there was both rill and sheet erosion which are two other forms of water-caused soil erosion. Undoubtedly there was also wind erosion on this field, but this form of accelerated soil erosion was not obvious in this or succeeding photographs of this field.
This accelerated soil loss was water erosion, meaning tht moving water was the primary agent of soil dislocation and removal. Wind erosion usually causes considerably greater solil erosion is the Great Plains Region, but this particular field had been particularily hardhit by water erosion. Tumble weeds in the erosion channel were both Russian thistle and kochia.
Washington County, Colorado. (And George Washington, "Father of American Agriculture" and first US president, would not be pleased or amused.) June.
61. Contrast in cover- Two more views of the cropland introduced in the preceding photograph showing conditions of water erosion on the unprotected bare soil which was the outcome of clean-farming (tillage so complete that inadequate crop residue remained to protect soil from the ravishes of wind and, most noticably in this instance, moving water.
In the foreground was native sod of mixed prairie which provided an in-effect complete cover of herbaceous vegetation that prevented soil loss. This vivid short set of slides furnished a contrast in stewardship and wise use consevation, a sharp dochotomy between land undergoing soil erosion due to improper farming practice and land protected by Mother Nature's own living blanket. Major grass species of the remnant mixed prairie included western wheatgrass, the dominant, along with blue grama, sideoats grama, sand bluestem, sand dropseed, needle-and-thread, cheatgrass, and smooth brome. The latter two were, respectively, a naturalized weedy annual and a naturalized agronomic species which can also be weedy.
Washington County, Colorado. June.
62. Healed by man's helping hand through the Conservation Reserve Program- Grassland restoration on highly erodible cropland in the Central High Plains. The most common grass in the draw (and a gully prior to reshaping and seeding) was western wheatgrass that was readily distinguished by its glaucous gray coloration. Sideoats grama was the grass of lighter green color and, overall, the most abundant grass on this restored mid-grass prairie. Blue grama had also been reseeded and was widespread. Sand dropseed and needle-and-thread were coming back in naturally. This latter development is a common occurrence on reseeded ranges. .
Washington County, Colorado. June.
63. More CRP sod- A former crop field on highly erodible (and marginal) land that was reseeded back to native mixed prairie community through the Conservation Reserve Program. This land in the High Plains of northeastern Colorado was now a restored grassland of western wheatgrass, sideoats grama, blue grama, silver bluestem, sand dropseed, along with the Old World, King Ranch, or yellow bluestem (Andropogon ischaemum= Bothriochloa ischaemum) and the always-there naturalized cheatgrass. Only the first three of these species were part of the CRP seeding mixture. The native silver bluestem and sand dropseed returned "on their own" as did latter two two exotic or introduced grasses which naturalized in this area. KR or yellow bluestem was introduced into this area for the reseeding of road cuts and tame pasture.
In addition to the three major native grasses of this seeding, big
bluestem and little bluestem are also included (at about 10% each)
in standard CRP mixes on "tightland" like that shown here.
On "sandy land", Indiangrass, sand bluestem, and prairie
sandreed are major native grasses recommended for CRP mixtures in
this area of the High Plains.
Washington County, Colorado. June.
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