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Small isolated wetlands in the southern Appalachian mountain region contain a disproportionate amount of the region's rare and uncommon herbaceous species. Many of these herbaceous communities may be threatened by invading trees and shrubs. We investigated changes in vegetative communities between 1994 and 2001 and the impact of woody encroachment upon herbaceous wetland communities in a southern Appalachian wetland complex in western North Carolina. We conducted a quantitative investigation of herbaceous, shrub and tree vegetation in forested and unforested fen and floodplain wetland sites. Additionally, soil chemistry, water level and precipitation data were collected. We found that woody encroachment was the strongest predictor of diminished herbaceous wetland communities, while water levels had the strongest positive relationship with herbaceous coverage.

Soil chemistry gradients exist in wetlands but information on the spatial variability of wetland soil properties is limited. Soils were collected from a small, depressional wetland (Carolina bay) in South Carolina to determine spatial patterns along an elevational gradient. The bay was divided into four quadrants and a transect was established in each quadrant. Plots were sampled at every 10-cm rise in elevation along the four transects. Samples from the A and B horizons were analyzed for soil texture, organic carbon (OC), pH, cation-exchange capacity (CEC), and exchangeable Ca, Mg, and K. Significant differences were noted for OC, clay content, CEC, and base saturation for the A horizon across the elevational gradient. The OC content of the A horizon decreased from 4.7% in the center of the bay to 2.7% near the rim. The CEC decreased from 26.0 [cmol.sub.c] [kg.sup.-1] in the center to 13.9 [cmol.sub.c] [kg.sup.-1] near the rim. Significant differences also were observed for pH, OC, CEC, sand, silt, clay, exchangeable Mg, Ca, and base saturation among the four transects. In the B horizon, there were no significant differences for any parameter across the elevational gradient, or among the four transects. The clay content of the B horizon was about 20%, compared with

Foliage of the dominant riparian canopy species of a blackwater stream flood-plain was collected from three sites and analyzed for C, cell walls, N, P, S, K, Ca, Mg, Al, Fe, Mn, Zn, Cu and B. Foliage was collected three times to compare nutrient concentrations after leaf-out (April), in midsummer (August) and before abscission (October). Several species occurred at two sites and Acer rubrum occurred at all three sites. Decreases in foliage C, N, S, P, K and Cu were noted for most species as the growing season progressed. Increases in foliage cell walls, Ca, Fe, Mn and B were also observed. The concentrations of foliage Mg, Al and Zn increased or decreased depending on species. Riparian species exhibit a wide range of foliage nutrient concentrations, particularly for K, Ca, Al, Mn and Zn. Separation of species based on gradients of foliage nutrient concentrations, especially Ilex opaca and Quercus spp., was clearly demonstrated by principal components analysis. Principal components were also used to examine the temporal separation of Acer rubrum at three sites. Separation of A. rubrum was most distinct in October although there were no significant differences in foliage nutrient concentrations of cell walls, Ca, Al, Mn, Zn and B., INTRODUCTION Seasonal variation of nutrient concentrations in foliage has been reported for several terrestrial forest species (Hoyle, 1965; van den Driessche, 1974; Woodwell, 1974; Ostman and Weaver, 1982; Chapin and [...]