Changes in plant species composition along an elevation gradient in an old-growth bottomland hardwood-Pinus taeda forest in southern Arkansas1

Journal of the Torrey Botanical Society, Jan-Mar 2005 by Grell, Adrian G, Shelton, Michael G, Heitzman, Eric

Diversity. Diversity in all vegetative layers in this study was generally found to increase with elevation. This pattern was similar to that found in others studies of wetland habitats (Bell 1974, 1980, Bell and del Moral 1977, Robertson et al. 1978, Frye and Quinn 1979). Vegetation in the lower elevations is subjected to frequent and sometimes strong flooding events, which restricts successful establishment to those species highly tolerant of such conditions (Barnes 1978, Menges and Waller 1983, Titus 1990). Bell (1980) found evenness to sharply decrease with increases in elevation. However, our findings indicate that evenness is relatively uniform for all vegetative layers along the elevation gradient. This difference might be explained by the fact that Bell (1980) sampled along an elevational gradient of about 15 m whereas our gradient was only 1.5 m.

1 The authors thank Potlatch Corporation, Arkansas Natural Heritage Commission, Arkansas Forest Resources Center, and USDA Forest Service, Southern Research Station for supporting our research at the Lost Forty.

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