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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 formed " a fairly distinct belt between the tall-grass
and mixed prairies" but that "has been almost completely removed"
by cultivation (Weaver and Clements in both editions [1929 and 1938] of
Plant Ecology).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 overextending the range of true prairie
eastward.
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). |
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| 2. Inflorescence of procupinegrass on a native
prairie hay meadow- Burkhart Prairie, Newton County, Missouri. June. |
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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).
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| 4. Inflorescene (spike) of nodding Canada wildrye - Erath County, Texas.
June. |
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| 5. Virginia
wildrye (Elymus virginicus)-
This wildrye species grows on the same general range types and geographic
region as nodding or Canada wildrye, but typically on more mesic and shaded
microsites. Frequently, however, these two species literally grow side-by-side,
and according to Gould (1975, p. 167), readily hybridize. An instructiver
exercise for beginning Agrostology students is to use different manuals
(eg. Hitchcoch and Chase, 1951 vs. Gould, 1975) and find that some specimens
will key to E. canadensis using
one authority and to E. virginicus
using a different author. Both species are highly palatable decreasers extending
from the eastern edge of tallgrass prairie through true prairie to mixed
prairie. The vertical shoots of the example shown clearly designate it as
E. virginicus. Border of tallgrass
hay meadow in island of Cherokee Prairie in Ozark Plateau. Ottawa County,
Oklahoma. June. |
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| 6. Individual plant of prairie dropseed- This is the most
widespread dominant species of the true prairie range type. Shown here is
the typical habit of this cespitose species. Scale is shown by the meter-long
walking stick. Hay meadow, Ottawa County, Oklahoma, July. |
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| 7.
Tall (= meadow) dropseed (Sporobolus
asper)- This species is actually a taxonomic “complex” with
three or four (or more) subspecies or varieties plus perhaps other closely
related Sporobolus species that are difficult
to differentiate and which often hybridize. S. asper is commonly second
only to S. heterolepis as a dominant or associate
species on tallgrass and true prairie range types. Sporobolus is one of the few Gramineae
genera whose fruit is an achene and not a caryopsis. Erath County, Texas.
October. |
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| 8. Inflorescence of tall dropseed The contracted panicles of
this species complex are partially to completely enclosed within the surrounding
leaf sheath (ie. at least some of the infloresences on individual tall dropseed
plants remain within the boot from which fruits are shed with the eventual
disintegration of this enveloping lower portion of the leaf). Erath County,
Texas. October. |
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| 9. Close-up of sward of true prairie- A consociation (to
use Clement’s term) of prairie dropseed but with its associate, prairie
dock (Silphium terebinthinaceum), existing almost as a co-dominant.A
bald knob, a dolomite glade (McClurg Glade), in the Ozark Mountains of Missouri.
Ava Ranger District, Mark Twain National Forest, Ozark County, Missouri.Note
the young sprouts of yellow wood or smoke tree (Cotinus obovatus).Maintained
by prescribed burning. FRES No. 39 (Prairie Ecosystem). Not described by
Kuchler or SRM. |
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