Research Article Post-Restoration Plant Community Changes in Grazed and Ungrazed Seasonal Wetlands in Florida

Seasonally inundated wetlands are threatened ecosystems worldwide and increasingly important targets for wetland restoration programs. However, restoring such ecosystems is difficult, as it requires mimicking the historical shifts between dry and flooded states. In this study, we evaluate the responses of agriculturally impacted seasonal wetlands to pasture-scale hydrological restoration. We selected 15 seasonal wetlands in central Florida (10 within restoration easements and five in unrestored pastures) and excluded cattle from five of the restored wetlands. We monitored each wetland from 2011 to 2016 to document potential changes in water levels, plant species richness, beta diversity, floristic quality, and cover of obligate wetland species. Vegetation responses to restoration were gradual and subtle, becoming detectable only five years following restoration. By 2016, restored wetlands had significantly lower cover of facultative upland species and higher cover of obligate wetland species. Species richness was higher in unrestored wetlands due to the presence of many facultative upland species. Beta diversity within wetlands and floristic quality based on coefficient of conservatism were not affected by restoration. We did not find strong effects of cattle exclusion on post-restoration diversity metrics, but we observed a large increase in the native grass, Panicum hemitomon Schult. This study showed mixed outcomes when measured against the goals of restoring wetland communities. It also highlighted the need for more active restoration approaches to regain historical communities or promote target species (e.g. Coleataenia abscissa (Swallen) LeBlond). We emphasize the need for costly restoration activities to be coupled with long-term monitoring to assess success.

Automated summary

Seasonally inundated wetlands are threatened ecosystems that require difficult restoration methods to mimic historical shifts. In this study, the responses of agriculturally impacted seasonal wetlands in central Florida to hydrological restoration were evaluated. The restoration led to gradual changes in vegetation, with lower cover of non-wetland species and higher cover of wetland species. Species richness was higher in unrestored wetlands, and restoration did not significantly affect beta diversity and floristic quality. Cattle exclusion showed limited effects on post-restoration diversity metrics. This study emphasizes the need for active restoration approaches and long-term monitoring to achieve successful wetland restoration.