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1. Dry Arctic Tundra— Barren Ground or Barren Land tundra with an eye-level view of the quintessential patterned ground with the polygon shape, the classic polygonal-patterned ground tundra. The Barren Ground tundra here is the tundra range type identified and described in considerable detail as Tussock Tundra (SRM 918). Prudhoe Bay, Alaska. July. No FRES designation for tundra. Dry tundra form of phase of Kuchler-117 (Watersedge Tundra). Alaskan Tundra biotic community of Brown et al. (1998).
2. The Tussock Tundra seen here is the drier end of this range type with sedges, especially Bigelow sedge (Carex bigelowii) and C. lugens, dominating the raised ground while tussock cottongrass (Eriophorumvaginatum ssp. vaginatum) occurs as almost exclusive single-species stands in the polygonal depressions. There are no shrubs or vascular forbs but there are occasional cryptogamic plants (cryptogam= plant reproducing by spores rather than seeds), these being nonvascular cryptogams like fruticose lichens known generally as reindeer moss (Cladonia rangiferina, C. stellaris or, by other lichenologists, Cladina rangiferina, C. stellaris) and cetraria lichens (Cetraria cucullata, C. islandica).
Of the various classifications and designations of tundra types, the simplest is likely the distinction between "dry tundra" and "wet tundra" for that with soils whose profiles have free internal drainage or impeded internal drainage, respectively. Obviously there are graduations between these two extremes (Bliss in Barbour and Billings [1988]), but the contrast can be substantial even at the local scale. In this landscape scale view, wet tundra is in the background by the Beaufort Sea and dry tundra is the vegetation in the foreground. Prudhoe Bay, Alaska. July. No FRES designation. K-117 (Watersedge Tundra). SRM 918 (Tussock Tundra). Alaskan Tundra biotic community of Brown et al. (1998).
3.Micro-relief of polygonal-patterned Barren Ground dry tundra complete with a Barren Ground Caribou (Rangifer articus= R. tarandus arcticus)— Caribou hoof prints are common in the depressions which here support Arctic sagegrush (Artemesia arctica) and infrequent Labrador tea (Ledum palustre ssp. decumbens) as well as the graminoids. Beaufort Sea in background with wet tundra adjacent to it. No FRES No. for Tundra Ecosystem. K-117 (Watersedge Tundra). Alaskan Tundra biotic community of Brown et al. (1998).
4. Wet tundra sandwiched between the Beaufort Sea— This small peninsula of tundra is the hydric extreme of the tundra types (using "tundra" in the narrow, restrictive sense for Arctic herbaceous cover types and excluding riparian and swamp vegetation types). It was designated Wet Meadow Tundra by the Society for Range Management (Shiflet, 1994) and the Graminoid-Moss Tundra by Bliss. It is a sedge-grass marsh though not as well developed as those of the Aleutian Islands even though it is Aleutian Tundra by Shelford (1963) criteria. Water sedge (the same Carex aquatilis as in the Rocky Mountain alpine) is the dominant species followed by few-flowered sedge (C. rariflora), and round sedge (C. rotundata) and, often locally dominant, tall cottongrass (Eriophorum angustifolium). Lichens are absent but the ground-- the soil surface-- layer is comprised of bryophytes (nonvsasculara, chlorophyll-containing, multi-cellular, spore-bearing primitive land plants). Most of these bryophytes are mosses-- true mosses (Musci)-- of several genera. Sedge-grass wet meadows or marshes are preferred ranges for muskoxen (Ovibos moschatus) as well as forage par excellence for the ever-present caribou. Prudoe Bay, Alaska. July. No FRES desigation. Predominately K-117 with local spots more closely described as K-116 (Cottonsedge Tundra). SRM 919 (Wet Meadow Tundra). Sedge-Moss Series in Alaskan (Coastal) Wet Tundra biotic community of Brown et al. (1998).
5. Avens Tundra- Arctic avens (Dryas integrifolia)-dominated low tundra in a wash zone of the Beaufort Sea— Drift wood shows this gravelly soil, a lithosol, to have frequent wave and outwash action from inland. Dryas tundra is generally interpreted as a seral community. Shelford (1963) viewed it as subclimax to heath or sedge climaxes. Bliss (in Barbour and Billings [1988]) described it as Low Arctic Semidesert Cushion Plant-Cryptogam. The water-filled depressions are called "ponds" though the larger one on the left is the Beaufort Sea. More precisely, the vegetation is a mosaic of Arctic avens-gravel ridges and a "hodge-podge" of sedge species from both Dry (= Tussock) Tundra (SRM 918) and Wet Sedge Meadow Tundra (SRM 919) discussed above. Within a few feet of one another are growing Arctic avens and water sedge with Bigelow sedge a dominant between. In addition to tolerating severe cold and wind these species must also tolerate periodic inundation of salty sea water from wave action. The rapidly drained gravel soil allows Dryas to persist. Prudoe Bay, Alaska. July. No FRES designation. Primarily K-118 (Dryas Meadows and Barren), but some K-117 (Watersedge Tundra) and K-118 (Cottonsedge Tundra).Variant of SRM 907 (Dryas). Variant or form of Alaskan Martitme Strand biotic community of Brown et al (1998).
6. Section of Trans-Alaska Pipeline across Barren Ground dry tundra— A scene of Patterned Ground Tundra with a Barren Ground Caribou keeping watch from a polygon ridge of soil created by frost-heaving. This shot demonstrates that when he sets his mind to it man can wisely manage and use natural resources for the greater good of the human race while still preserving the priceless heritage of a God-given natural environment. This scene symbolizes and encapsulates the high ideals of wise-use conservation and multiple use of natural resources.
7. Colony of sea lyme grass or variously American dunegrass, American
beachgrass, and, probably most recognizable to rangemen, beach wildrye
(Elymus mollis= E. arenarius subsp. mollis)-
This rhizomatous grass is a pioneer or colonizer species of wet dunes
along the Pacific Coast from northern California to Alaska. In this
widely recognized role sea lyme grass was discussed by Polunin (1960,
ps. 371, 399, 400, 548, 566, 569), Shelford (1963, ps. 139, 200-201,
204), Chabot and Mooney (1985, ps. 299-301, 309-313), Barbour and Johnson
in Barbour and Major (1995, ps. 225-226, 229-231, 236, 240, 255, 257),
and Bliss in Barbour and Billings (2000, ps. 15, 22). Barbour (1990,
ps. 28-29, 31-33) and Pickhart and Sawyer (1998, ps. 7-11, 34-35, 37,105-106)
explained how this native Pacific dunegrass was threatened by the vigerous,
alien sand dune binder European beachgrass (Ammophila
arenaria). The latter is a local, naturalized man-made (= anthropogenic)
grassland and was shown and discussed with the Grassland slides above.
Logically, American beachgrass or beach wildrye could (for consistency
as to kind of vegetation should have) been included with grasslands.
It was included here with the other slides from the Arctic to be consistent
as to region. Recall that "tundra" is used (actually misused) as if
synonymous with Arctic and that the Society for Range Management (Shiflet,
1994, ps. 121-141) avoided this error and discussed "Rangeland Cover
Types of the Alaska Region", including the rangeland cover type shown
here, SRM 903 (Beach Wildrye-Mixed Forb). Prudoe Bay, Alaska. July.
Beach wildrye dunes in California were mapped by Kuchler (1977) on the
Natural Vegetation of California as a component of Unit 50 (Northern
Seashore Communities, Elymus-Baccharis), part of Formations of Coastal Complexes.
This colony of beach wildrye represents the pure form of this range cover type. It is a pioneer seral stage and an example that cover or dominance types are not always climax vegetation, a point repeatedly noted in various points in this publication. That argument, however, can be turned on its head to illustrate the concept of patch dynamics or gap theory so central in Landscape Ecology. At landscape-scale due to disturbances (= perturbations) there are areas of naturally occurring vegetation at all seral stages such that there is a mosaic of vegetation at various stages of development toward climax or potential natural vegetation. This is the concept or, more precisely, the view or perspective of patch dynamics or shifting gaps. It is an application of Clementsian "dynamic vegetation" or "dynamic plant ecology". The key attribute in this relatively recent outlook is placing more emphasis on local changes in vegetation rather than putting emphasis on the general climax (ie. highlighting seral stages rather than seral termination; focusing relatively more attention on development than on stability or the "developed" vegetation). It is merely a shift in emphasis in order to study and manage other things.
Patch dynamics or gap (from gaps in forest canopies caused by disturbance) theory posits the view that even in pre-human vegetation or vegetation before man could alter it ("virgin" or "pristine" vegetation) natural disturbances of all sorts (eg. fires, beach erosion, wind and ice storms, disease, buffalo overgrazing, insect outbreaks, avalanches) kept the vegetation at the scale of region or even landscape in all stages of succession, a mosaic of ever-changing seral stages (thus the terms patch dynamics, shifting mosaics, shifting gaps). For example the pre-Columbian or even pre-Indian virgin forests of North America were not mile after mile of old-growth forest but patches of forests at all stages of plant succession developing back toward climax old-growth. At regional or landscape scale the condition would be in the shifting-mosaic steady state (Perry, 1994, p. 137).
In the view of shifting mosaic or patch dynamics the colonizing beach wildrye, while not climax, is a major part of vegetation growing on habitats that have high disturbance regimens like beach foredunes. Seral vegetation is probably less common in range cover types that are less exposed to major disturbances which induce retrogression and re-start secondary succession (eg. a tallgrass prairie in which a typical prairie fire does not cause retrogression, a beech-sugar maple forest less prone to forest fires and hurricanes). By comparison, seral vegetation may have been "the rule rather than the exception" on beach and dune. This would explain why the seral beach wildrye-forb vegetation is a range cover type and the first-year vegetation of an old-field in the bluestem prairie region was not so recognized.
8. Beach wildrye, sea lyme grass, or Pacific beachgrass- This look at a dune-colonizing grass is a lesson in the ecotype concept or ecological versus taxonomic definition of the taxon called species. The description of the beach wildrye-forb cover type (SRM 903) distinguished between Elymus arenarius subsp. mollis var. villosissimus around the Bering Sea which is seen here and E. arenarius subsp. mollis var. mollis of the Aleutian Islands and Prince William Sound. The two varieties intergrade, however, where their ranges overlap illustrating the concept of the ecocline. Range Ecology students are referred to Barbour et al. (1999, ps. 40-50) for an explantion of the ecotype/ecocline phenomenon. Prudoe Bay, Alaska. July.
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