Using Spatial Modeling to Improve Wetland Inventories in Great Smoky Mountains National Park

Abstract

Wetlands are an ecologically important yet threatened plant community type in many natural areas. Inventory and monitoring are essential components of protecting, managing, and restoring wetland resources. However, many challenges currently exist for resource managers looking to perform a comprehensive inventory of wetlands throughout expansive, topographically complex, and/or remote natural areas. Here we present ongoing work in Great Smoky Mountains National Park (GRSM) that is addressing these challenges using spatial modeling to inform on-the-ground surveys. Wetland communities occur throughout GRSM at all elevations but tend to be relatively small and patchily distributed. While simple models based on low (<10%) slope are informative to wetland surveys at low elevations (<1067 m), such models become ineffective in steep topography at high elevations. To address this issue, we developed and implemented parkwide maximum entropy (Maxent) wetland habitat suitability models incorporating 24 environmental variables. Using these models to guide wetland survey efforts for three years, we identified and mapped 93 new wetland occurrences and more than doubled our previous high-elevation (≥1067 m) wetland inventory in roughly half the time. Maxent modeling is a relatively easy to use tool that can help resource managers plan, prioritize, and implement field inventories efficiently and effectively. We encourage natural areas managers to adopt similar spatial modeling approaches to guide the detection of unique, patchily distributed plant community types such as glades, barrens, balds, or rock outcrop communities.