Vascular flora of three watersheds in the Fernow Experimental Forest and factors influencing species composition of the herbaceous layer

Herbaceous layer communities respond to a number of environmental variables in forests: thus, study of the herb layer is essential for a more complete understanding of the forest ecosystem. The objectives of this study were to (1) describe the flora of the watersheds. (2) describe the species richness and diversity of watersheds 3, 4 , and 7 of the Fernow Experimental Forest, Parsons, West Virginia, and (3) examine stand and soil variables and their influence on the herbaceous communities or the forest. Watersheds were selected on the basis of stand age/history (WS3 20yr, clearcut; WS7 20 yr. clearcut and herbicide: WS4 80 yr, control). Each watershed was sampled foristically by walking its entirety four times from May through August. The voucher specimens and habitat data collected from this sampling method were used to create an annotated species 1ist for all three watersheds, thus providing baseline data for future studies. In addition to the floristic survey, the herb layer was sampled within 15 0.04-ha circular plots per watershed. All vascular plants \u3c 1 -m in height within 10 l-m2 subplots per plot were identified to species and cover (1/4)was estimated. One 10-cm soil sample was collected from two subplots in each plot. Texture values were determined and nutrient analyses were conducted on each soil sample. Extractable Ca, K, Mg, P, organic matter, and pH were all determined. All subplot values were averaged to give means per plot and watershed. These data suggest that (1) herb layer species composition, richness and diversity do not vary with stand age in these forests, (2) response of the herb layer to environmental gradients is a function of stand history and aspect, and (3) species diversity response to elevation is a function of herb layer species and communities to gradient conditions