1.
Frederic E. Clements, arguably the greatest range ecologist of all time, and John
E. Weaver, the man who know more about the North American prairie and the grasslands
of the Great Plains than anyone who ever trod sod, were adamant that true prairie
was the dominant climax form of prairie per se and not bluestem-Indiangrass
tallgrass prairie, which was a separate form, another vegetation type in current
parlance. True prairie in their view (Weaver and Clements, 1938, ps. 518-519)
"occupies a fairy distinct belt between the tall-grass and mixed prairies"
extending from southern Manitoba through central Kansas and into southern Oklahoma.
However, "cultivation has almost clompetely removed the true prairie over
most of its area" with natural boundaries having to be hypothetically reconstructed
from small, scattered remnants. (Weaver and Clements, 1938, p. 518) listed major
dominants of true prairie (in order): Stipa spartea, Sporobolus asper,
S. heterolepis, Andropogon scoparius, Koleria cristata, Agropryon
smithii, and Bouteloua curtipendula "often with Andropogon
furcatus [= gerardii] and Sorgastrum nutans from the postclimax".
Weaver and Clements in both editions [1929 and 1938] of Plant Ecology held
to this interpretation as did their colleague Shelford (1963, p. 334) .As to tallgrass
species, Weaver and Clements explained how removal of buffalo and decrease of
fires led to replacement of even short grasses like buffalograss (Buchloe
dactyloides) by the bluestems (Andropogon spp.) and other tallgrass
genera. They noted " the belief of the pioneers that the bluestems (Andropogon)
followed in the wake of the settlers and drove out the buffalo grass ". "
The advance of the tall Andropogons over much of the true prairie is attested
by scientific accounts of its composition" (Weaver and Clements, 1938, ps.
458-460, 516, 518-521).
Dodd (In: Gould, 1968, ps.325-328) provided a
detailed description of true prairie, but he erred by omitting tallgrass prairie
and, instead, including it in true prairie thereby eliminating a description of
the tallgrass grassland, the Kuchler-66 (Bluestem Prairie), and therby overextending
the range of true prairie eastward. Nonetheless, Dodd did recognize the Stipa-Sporobolus
dominated climax grassland communities (ie. true prairie) as a major and geographically
large, even immense, (regional scale) unit of potential natural vegetation. Dodd
was unique among more recent (post-Clementsian era) workers in this interpretation,
and he was correct. In describing rangeland cover types, the Society for Range
Manageament (Shiflet, 1994) was remiss in leaving out the Stipa-Sporobolus
(with associates like A. scoparius, K. cristata, and B.
curtipendula) range type. Ditto for omission of the Clementsian true prairie
in standard contemporary descriptions/discussions of North American grasslands.
For example, Simms and Risser (in Barbour and Billings, 2000, ps. 333-345) excluded
true paririe after previously listing (in Barbour and Billings, 2000, p. 331)
the climax grasslands of Weaver and Clements (1929, 1938), including the Stipa-Sporobolus
true prairie association. Obviously true prairie is no longer a major existing
unit of North American grassland which is apparently the reason for its later
exclusion by Sims and Risser, but it does exist and is a major range type to livestock
operators, nature preservtionists, biologists, and other conservationists dependant
on and concerned about its wise use and proper management. Furthermore, as a unit
of potential natural vegetation-- a transition (" abroad ecogtone"[Weaver
and Clements, 1938, p. 519]) between tallgrass and msxed prairies-- it should
be recognized. Even kuchler (1964, 1966) missed the Stipa-Sprorbolus climax
grassland as potential natural vegetation.
Weaver and Clements (1938, p. 518) interpreted S. spartea, S. asper, and S. heterolepis as the "most characteristic dominants" because these species did not exist as dominants in any of the other climax grasslands (associations). To these pioneer plant ecologists who knew the grasslands at the time when they were being plowed under it was this feature of restricted dominance rather than extent or area of land dominated that was key and therefore indicative of true prairie, the ecotone between tallgrass and mixed prairie associations. Theirs' was a continent-wide perspective as the great grasslands were being highly altered-- in many cases destroyed-- by industrial man. It was a synoptic view that none thereafter could see. For this reason, current and future ecologists have no choice but to accept the eye-witness accounts of these pioneers of Grassland Ecology.
Here is a sample of true prairie, and one of the John Weaver's favorites. Scene of Nine-Mile Prairie (9 miles form his beloved University of Nebraska). The three characteristic dominants of true prairie were porcupinegrass (Stipa spartea), prairie dropseed (Sporobolus heterolepis) and tall dropseed . Besides these species this view includes little bluestem, Junegrass (Kolera cristata) and the introduced smooth bromegrass (Bromus inermis). August and, most appropriately, a drought. Lancaster County, Nebraska. FRES No. 39 (Prairie Ecosystem). No Kuchler or SRM designation (remarkable given the body of evidence that supports distinction between true and tallgrass prairies).
3. Canada wildrye (Elymus canadensis)- This is a consociation (a community having a single dominant species, sometimes having a single species period as a natural single species stand; synecological term coined by F.E. Clements) of Canada or nodding wildrye on a floodplain on the Texas Grand Prairie (a tallgrass prairie). The wildryes (Elymus spp.) are one of the more important and widely distributed genera of cool-season grasses in the bluestem-dominated tallgrass prairies and oak-hickory-tallgrass savannas. Erath County, Texas. June. FRES No. 39 (Prairie Ecosystem), one form or subunit of K-669 Bluestem Prairie).