Association of Edaphic Factors and Vegetation in Several Isolated Appalachian Peat Bogs

STEWART, C. N., JR. AND E. T. NILSEN (Biology Department, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061). Association of edaphic factors and vegetation in several isolated Appalachian peat bogs. Bull. Torrey Bot. Club 120: 128-135. 1993.-The vegetation of five Appalachian bogs (one site in Tennessee and four in West Virginia) was sampled using a point-quarter method. Rubus hispidus had the highest importance value in the Tennessee site and Vaccinium oxycoccus in the West Virginia sites. Major differences and similarities in vegetation are summarized, and comparisons are made with northern peat bogs, which are also dominated by dwarf shrubs. The dominant growth form in all the bogs was recumbent shrub, which was two to three times more important than other growth forms. Within the growth form, the importance values of R. hispidus (Rosaceae) and the evergreen recumbents (Ericaceae) were inversely related. Among sites, the importance value of R. hispidus was positively associated with soil nutrient status (r2 = 0.99), while those of the ericaceous recumbents were negatively associated with nutrients (r2 = 0.94). This relationship was consistent for all macronutrients except nitrate. This relationship is important since eutrophication may exacerbate the decline of Appalachian bogs and indigenous vegetation. As bogs become more minerotrophic, we predict a shift in dominance from evergreen to deciduous species. Specifically, the importance of R. hispidus may increase as the importance of bog ericads decreases.