VEGETATIVE STRUCTURE AND COMPOSITION OF SOUTHERN APPALACHIAN RIPARIAN FORESTS

HEDMAN, CRAUG W. (Southlands Experiment Forest, International Paper, Bainbridge, GA 31717) AND DAvID H. VAN LEAR (Department of Forest Resources, Clemson University, Clemson, SC 29634-1003). Vegetative structure and composition of Southern Appalachian riparian forests. Bull. Torrey Bot. Club 122: 134-144. 1995.-Vegetative characteristics of twelve Southern Appalachian riparian forests were sampled as part of a larger study which examined functional attributes of riparian zones. Riparian forests were representative of the mixed mesophytic forest, eastern hemlock forest, and transitions between these types. Earlyand mid-successional stages were generally dominated by an overstory of pioneering shade-intolerant species and had an even-aged structure. The diameter distribution of these relatively young stands of mixed species was typically inverse J-shaped. Late-successional and old-growth stages were dominated by shade-tolerant or moderately tolerant overstory species and were uneven-aged. Diameter distribution in these older stands approximated a rotated sigmoid curve. Rhododendron (Rhododendron maximum L.) was the dominant understory species and controlled understory and midstory composition. Characterization of riparian forests in different stages of succession will help understanding of vegetative processes and forms the basis of subsequent ecological studies of riparian functional dynamics.