Spatially prioritizing wetland conservation decisions for climate adaptation: An Illinois case study

Abstract Amid shifting federal regulations and intensifying climate extremes, wetlands across the US are increasingly at risk of degradation and conversion, especially in Illinois where 70.1–73.3% of the remaining wetland area is unprotected. However, risks to wetlands and their societal co-benefits are unevenly distributed across the state due to spatial variation in climate and land use dynamics. Thus, to identify state regions with similar wetland management needs, we synthesized existing datasets to map four wetland ecosystem services, unprotected wetland areas, wetland areas recently converted to agriculture and impervious cover, and projected changes in four climate extremes. This revealed that wetland ecosystem services are greater in counties with more conversion and climate risk. In addition to having the most unprotected wetland area, southwestern IL has the most wetland area recently converted to agriculture and projected increases in three of four evaluated climate extremes, underscoring the need to conserve the region’s unique and biodiverse wetlands. Enhancing and preserving existing wetlands is also most important in northeastern IL because it has the most wetland protection yet greatest wetland area recently converted to impervious cover and projected reductions in frost days. Across northwestern and southeastern IL, restoring wetlands for climate resilience should be highest priority due to the region’s low wetland services and intermediate to high future climate extremes, including excess heat and longer dry and wet spells. Because our approach relied on widely available public data, it can be readily applied beyond Illinois to strategically prioritize areas for wetland protection, enhancement, and restoration.