Delineation of spatial boundaries in a wetland habitat

A probabilistic similarity technique was used to locate spatial and temporal biotic boundaries in two west-central Florida marshes. By investigating spatial and temporal boundaries simultaneously, insights into community dynamics that were not apparent from examination of either kind of boundary in isolation were obtained. Recurring spatial boundaries in both marshes were found at the edges of deeper basins or near the edges of the marshes. Spatial boundaries shifted more frequently in Big Marsh, a large, well-drained marsh with extensive transition zones, than in Little Marsh, a poorly drained marsh with a relatively stable water level. Temporal boundaries occurred most frequently in autumn in both marshes. Temporal boundaries were associatd frequently with changes in spatial boundaries in Big Marsh, but only infrequently in Little Marsh. Simultaneous investigation of spatial and temporal boundary dynamics can be used to identify transition zones within marshes and can be used to determine from one year seasonal sampling surveys whether wetland boundaries will remain stable over more than one year.