Informing the Conservation of Ephemerally Flooded Wetlands Using Hydrologic Regime and LiDAR-Based Habitat Assessments

Abstract

Integrated assessments of wetland hydrologic regimes and other environmental factors are key to understanding the ecology of species breeding in ephemerally flooded wetlands, and reproductive success is often directly linked to suitable flooding regimes, both temporally and spatially. We used high-resolution Light Detection and Ranging (LiDAR) data to develop bathymetric stage–flooded area relationships, predict spatial extent of flooding, and assess vegetation structure in 30 pine flatwoods wetlands. For a subset of wetlands with monitoring wells, we then integrated bathymetric and water level data to create multi-year time series of daily flooded areas. We then related the observed flooded areas to topographic and landscape metrics to develop models predicting flooded extents in wetlands without monitoring wells. We found that stage–area curves varied depending on wetland size and bathymetry, such that a one-cm increase in water depth could generate flooded area increases ranging from hundreds to thousands of square meters. Flooded areas frequently fragmented into discrete flooded patches as wetlands dried, and there was a weak positive correlation between hydroperiod and mean flooded area across multiple years (r = 0.32). To evaluate the utility of using LiDAR-derived data to support the conservation of wetland-breeding species, we combined metrics of flooding and vegetation to map potentially suitable habitat for the imperiled reticulated flatwoods salamander (Ambystoma bishopi). Overall, projects focusing on the ecology of wetland-breeding species could gain a broader understanding of habitat effects from coupled assessments of bathymetry, water level dynamics, and other wetland characteristics.