PARENT SESSION
Contributed Oral Session 58: Forest Ecology: Riparian Areas
Tuesday, August 9, 1:30 PM - 5:00 PM, Meeting Room 514 A, Level 5, Palais des congrès de Montréal
Riparian vegetation structural variability and linkages with stream geomorphology in the Lake Champlain Basin, Vermont.
Copeland, Erin*,1, Keeton, William*,1, Sullivan, Mazeika, 1 University of Vermont, Burlington, VT, USA
ABSTRACT- Structural variability in northeastern U.S. riparian forests is poorly understood. We hypothesize that structure varies more within floodplain than upland forests and that patterns of structure emerge across riparian zones due to the high frequency and interaction of natural and anthropogenic disturbances. Structural variability has dramatic effects on river systems resulting from hydrologic, geomorphic, and biotic processes. In theory, if natural and human factors create distinctly different structural conditions that relate to riparian functions, then riparian forest structure may serve as a useful indicator of stream reach condition. We developed a classification system that quantifies the range of variability in riparian forest structure and tested the utility of the system as a predictor of channel geomorphology. This study focused on floodplain forests in the Lake Champlain Basin, VT. We sampled a total of 37 sites with a range of vegetation types; wet meadow, shrub wetland, floodplain forest and terrace forest. Forest structure was sampled within wet meadow, floodplain forest and upland forest landforms using multiple forest inventory methods, Leaf Area Index meters and laser rangefinders. Data was analyzed using ANOVA, linear regressions and multivariate analyses. Cluster analysis and subsequent ANOVA identified site groupings with similar structural characteristics. Sites clustered around high basal area, low coarse woody debris volume and shrub density; at least one cluster has large anthropogenic influences. Leaf Area Index varied within landforms (p=0.013) and among sites. Stream-forest linkages are also evident; basal area is a significant predictor of stream geomorphic assessment scores (multiple R-squared: 0.52, p<0.001). This research will provide information about riparian forest structural variability, contribute to a larger watershed classification project and improve riparian restoration efforts in the Lake Champlain Basin, VT.
Key words: riparian forest structure, stream geomorphology