Groundlayer vegetation gradients across oak woodland canopy gaps1

Abstract

Abstract Pavlovic, N., R. Grundel, and W. Sluis (U.S. Geological Survey, Great Lakes Science Center, 1100 N. Mineral Springs Rd., Porter, IN 46304). J. Torrey Bot. Soc. 133(2): 225–239. 2006.—Frequency of groundlayer plants was measured across oak woodland canopy gaps at three sites in northwest Indiana to examine how vegetation varied with gap size, direction along the gap edge, and microhabitat. Microhabitats were defined as under the canopy adjacent to the gap, along the gap edge, and within the gap. Gap-sites consisted of gaps plus adjacent tree canopy. Gaps were classified as small (16 ± 1 m2), medium (97 ± 8), and large (310 ± 32). Neither richness nor diversity differed among microhabitats, gap sizes, or edges. Similarity between microhabitats wthin a gap-site increased as the distance between plots decreased and as the difference in PAR decreased, the latter explaining twice the variation in percent dissimilarity compared to Mg concentration, A horizon depth, and litter cover. Diervilla lonicera, ...