Lateral Zonation of Trees along a Small Ohio Stream

Author Institution: Department of Botany and Bacteriology, Ohio Wesleyan UniversityRiparian-vegetation patterns along a small stream in Ohio were examined with multivariate and graphical analyses. The study focused on elevational differences in larger tree species (>10 cm DBH = diameter at breast height) on a floodplain bench, floodplain slope, and upland terrace. The three habitat zones showed differences in floral assemblages related to the flooding tolerance of tree species, the floodplain bench showing ash-maple dominance and the other habitats yielding maple-beech-oak dominance. The floral differences were likely attributable to natural and human impacts, particularly stream flooding and possibly past logging. The results and a literature review suggest that hydrologic disturbances (for example, flooding) create predictable, parallel patterns in floral assemblages along a lateral (stream-edge to upland) gradient. Riparian assessments in the lateral dimension can provide information to predict the effects of anthropogenic instream-flow alterations on riparian ecosystems, including small tributaries