Jerry Baskin
Friday, October 17, 2008 - 9:30-10:00
Two primary types of herbaceous plant-dominated vegetation that occur on shallow rocky calcareous soils in eastern USA, where temperate deciduous forest is the climatic climax, are cedar glades (CGs) and xeric limestone prairies (XLPs). On his map of vegetation types of conterminous USA, A. W. Kuchler (1964, Amer. Geogr. Soc. Spec. Publ. No. 36) included the perennial grass-dominated glades (XLPs) of the Ozarks and cedar glades (s. lat.) of southeastern USA under Juniperus-Quercus-Sporobolus (his vegetation type 83). Neither have biologists working in various eastern USA states, e.g. J. T. Curtis (1959) Vegetation of Wisconsin, UW-Madison Press, recognized differences between the two types; Curtis classified cedar glades as savannas. However, there are some clear differences between CGs and XLPs (J. Baskin, C. Baskin, and P. Lawless. 2007. Bot. Rev. 73: 303-325), e.g. soil depth (generally much shallower in CGs), dominant plants (C-4 annual grasses in CGs vs. C-4 perennial grasses in XLPs), and origin (natural edaphic climax for CGs vs. anthropogenic disclimax for XLPs, except perhaps for the Ketona dolomite glades in Alabama). It follows from this last comparison that XLPs need to be managed to maintain them, whereas CGs do not. This talk will review the geographical distribution, flora, and vegetation of these two vegetation types. A brief comparison also will be made of eastern USA XLPs and western USA limy prairies, etc. and of eastern XLPs/CGs and alvars in the Great Lakes region, Canada/USA, and the Island of Öland, southern Sweden.
Keywords: ANTHROPOGENIC DISCLIMAX, CEDAR GLADES, C-4 GRASSES, EDAPHIC CLIMAX, XERIC LIMESTONE PRAIRIES