TY - JOUR
T1 - Scale-dependent classification of xeric limestone prairies
T2 - Annual or perennial grasslands?
AU - Lawless, Patrick J.
AU - Baskin, Jerry M.
AU - Baskin, Carol C.
PY - 2006
Y1 - 2006
N2 - Xeric limestone prairies (XLPs) are herbaceous plant communities that occur on shallow rocky calcareous soils from Missouri and Pennsylvania south to Arkansas and Georgia (U.S.A.). There has been considerable confusion regarding the classification of XLPs due to their similarity with limestone cedar glades (LCGs), an edaphic climax community type restricted to unglaciated southeastern United States. Although C4 perennial grasses typically are the dominant taxa in XLPs, portions of sites with extremely shallow soils (≤ 0.1 m) are typified by local dominance of Sporobolus vaginiflorus (Torr, ex Gray) Alf. Wood, a C4 summer annual grass that is the characteristic dominant in LCGs. In this study, we assess the relative importance of C 4 perennial grasses versus S. vaginiflorus in XLP community types identified in Kentucky over a range of scales. We then use these data to analyze variability in XLP vegetation and physical environmental conditions and to further compare XLPs with LCGs. Sporobolus vaginiflorus had high frequencies in many of the fine-scale community types (0.01 and 0.1 m2) identified in this study. However, dominance of C4 perennial grasses (particularly Schizachyrium scoparium (Michx.) Nash) in all 12 of the community types identified at the largest scale (100 m2) is indicative of the relatively small areal extent of extremely shallow-soiled regions in XLPs. XLPs also differ from LCGs in that the former generally lack early-stage primary successional community types dominated by cryptograms and/or C3 annual forbs. Thus, the results of our study suggest that the total range of environmental conditions and the variety and extent of plant community types present in a site should be considered when classifying the vegetation of calcareous rock outcrop communities in the eastern United States.
AB - Xeric limestone prairies (XLPs) are herbaceous plant communities that occur on shallow rocky calcareous soils from Missouri and Pennsylvania south to Arkansas and Georgia (U.S.A.). There has been considerable confusion regarding the classification of XLPs due to their similarity with limestone cedar glades (LCGs), an edaphic climax community type restricted to unglaciated southeastern United States. Although C4 perennial grasses typically are the dominant taxa in XLPs, portions of sites with extremely shallow soils (≤ 0.1 m) are typified by local dominance of Sporobolus vaginiflorus (Torr, ex Gray) Alf. Wood, a C4 summer annual grass that is the characteristic dominant in LCGs. In this study, we assess the relative importance of C 4 perennial grasses versus S. vaginiflorus in XLP community types identified in Kentucky over a range of scales. We then use these data to analyze variability in XLP vegetation and physical environmental conditions and to further compare XLPs with LCGs. Sporobolus vaginiflorus had high frequencies in many of the fine-scale community types (0.01 and 0.1 m2) identified in this study. However, dominance of C4 perennial grasses (particularly Schizachyrium scoparium (Michx.) Nash) in all 12 of the community types identified at the largest scale (100 m2) is indicative of the relatively small areal extent of extremely shallow-soiled regions in XLPs. XLPs also differ from LCGs in that the former generally lack early-stage primary successional community types dominated by cryptograms and/or C3 annual forbs. Thus, the results of our study suggest that the total range of environmental conditions and the variety and extent of plant community types present in a site should be considered when classifying the vegetation of calcareous rock outcrop communities in the eastern United States.
KW - Cedar glades
KW - Community classification
KW - Rock outcrop
KW - Scale
KW - Xeric limestone prairies
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U2 - 10.3417/0026-6493(2007)93[455:SCOXLP]2.0.CO;2
DO - 10.3417/0026-6493(2007)93[455:SCOXLP]2.0.CO;2
M3 - Article
AN - SCOPUS:33751045605
SN - 0026-6493
VL - 93
SP - 455
EP - 464
JO - Annals of the Missouri Botanical Garden
JF - Annals of the Missouri Botanical Garden
IS - 3
ER -