Trajectories of Vegetation Response to Water Management in Taylor Slough, Everglades National Park, Florida

Abstract

Ecosystem management practices that modify the major drivers and stressors of an ecosystem often lead to changes in plant community composition. This paper exam- ines how closely the trajectory of vegetation change in seasonally-flooded wetlands tracks management-induced al- terations in hydrology and soil characteristics. We used trajectory analysis, a multivariate method designed to test hypotheses about rates and directions of community change, to examine vegetation shifts in response to changes in water management practices within the Taylor Slough basin of Everglades National Park. We summarized vegetation data by non-metric multidimensional scaling ordination, and ex- amined the time trajectory of each site along environmental vectors representing hydrology and soil phosphorus gradi- ents. In the Taylor Slough basin, vegetation change trajec- tories closely followed the hydrologic changes caused by the operation of water pumps and detention ponds adjacent to the canals. We also observed a shift in vegetation com- position along a vector of increasing soil phosphorus, which suggests the need for implementing measures to avoid P- enrichment in southern Everglades marl prairies. This study indicates that shifts in vegetation composition in response to changes in hydrologic conditions and associated parameters may be detected through trajectory analysis, thereby provid- ing feedback for adaptive management of wetland ecosystems.