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Appalachian mountain wetlands are uncommon and diverse ecosystems; however, they are often susceptible to extensive alteration or destruction due to coal mining, highway construction, and quarrying. This study aimed to determine vegetation composition at three pristine wetlands and establish relationships with previously reported hydrologic, edaphic, and porewater characteristics to provide baseline data that could enhance wetland mitigation or restoration projects. Herbaceous vegetation was assessed by visually estimating percent cover for bryophyte and vascular species and by determining stem density for vascular taxa using 1 m2 quadrats located along transects. Multiple response permutation procedures (MRPPs) based upon importance values confirmed that species composition differed significantly (P < 0·001) among the sites. Nonmetric multi-dimensional scaling (NMDS) indicated that soil moisture conditions during the fall, soil chemistry, and porewater chemical composition influenced plant community composition. The first wetland (Martins Fork) was primarily dominated by Osmunda cinnamomea, Osmunda regalis, and Sphagnum palustre in response to drier soil during the fall season, higher soil pH, and weakly minerotrophic soil and porewater. The second wetland (Kentenia) was overwhelmingly dominated by S. palustre due to lower soil pH and persistently high water levels. Vegetation at the third wetland (Four Level) was distinguished by strongly dominant Scirpus polyphyllus and Glyceria striata and responded to higher soil and porewater Ca, Mg, and P concentrations as well as a light intensity gradient. The diverse vegetation and physico-chemical characteristics indicate that these sites, although small in size, support regional biodiversity and are potential reference wetlands. Copyright © 2011 John Wiley & Sons, Ltd.

Redox potentials (Eh) were monitored bimonthly and porewater chemistry was analyzed seasonally at three slightly-acidic, high-elevation Kentucky wetlands that differed in hydrology, parent materials, and vegetation. At all sites, Eh values were below 300 mV, which indicated that reducing conditions persisted within the upper 90 cm and fluctuated mainly within the range of iron and sulfate reduction. Significant relationships of Eh values with depth were observed only at the Martins Fork wetland, where precipitation was the primary water source. The strongest and most stable reducing conditions, observed at the Kentenia site, reflected consistently high water levels, which were sustained by ground water. The third wetland (Four Level) was distinguished by irregular Eh fluctuations coinciding with strong seasonal ground-water upwelling. Although Fe3+ and SO4 2− were the primary terminal electron acceptors in all wetlands, porewater chemistry also varied significantly by season and soil depth in response to piezometric water level fluctuations. Additional factors that influenced porewater chemistry included: (1) the presence of limestone parent materials that affected porewater pH, Ca2+, and Mg2+; and (2) the prevalence of sphagnum moss or graminoid species that influenced dissolved organic carbon, CO2, and CH4. Results from this study indicated the diverse range and importance of multiple factors in controlling biogeochemical processes and properties in small, high-elevation Appalachian wetlands.

Hydrologic patterns and soil characteristics were investigated at three high-elevation wetlands in southeastern Kentucky, Martins Fork, Kentenia, and Four Level. Despite below-normal precipitation, water tables at all sites remained within 35 cm of the surface and fluctuated seasonally with peak heights during early spring. Seasonal precipitation contributed substantially to Martins Fork hydrology, while ground water was the primary hydrologic source for Kentenia and Four Level. Vertical hydraulic gradients varied among the sites. Martins Fork was distinguished by strong seasonal downwelling, while Kentenia and Four Level exhibited upwelling and downwelling patterns. All sites exhibited prominent soil hydromorphic features immediately below the surface horizon, moderate organic carbon content (< 6.5%), and a pH range between 4.4 and 6.2 according to the buffering capacities of local lithologies. The sites were dominated by sandy loam texture and siliceous mineralogy, reflecting the influence of s...