Wetlands Research Program. Evaluation of Methods for Sampling Vegetation and Delineating Wetlands Transition Zones in Coastal West-Central Florida, January 1979-May 1981

摘要

Eight wetland types in west-central Florida were studied to formulate a method for determining the upper limits of wetlands, defining the boundaries of transition zones, and distinguishing both from the adjacent wetlands. The study was conducted in two phases. Phase I was an evaluation of vegetation sampling methods to determine procedures that most efficiently achieved an accurate representation of changes in abundance and composition of the more common plant species. The best method proved to be sampling of shrubs in 1- x 4-m quadrats and herbs in 1- x 1-m quadrats along contiguous 1-m segments of transects placed parallel to the moisture gradient. Trees were not adequately sampled by the method because the large areas required for adequate sampling often extended past the transition zone into adjacent upland or wetland areas. Frequency and percent cover were found to be the most rapidly employed and useful vegetational parameters for determining wetland boundaries. Phase II of the study consisted of evaluating two analytical methods for delineating transition zone boundaries. The first method consisted of calculating percent similarity between consecutive quadrats along the transects. The second method involved calculating weighted averages for all species based on the average distance of each species from the wetland endpoint of the transects. Calculation of percent similarity values entailed fewer calculations and provided less ambiguous boundary delineations.