PNNL

Abstract

Inland wetlands are hotspots of diverse and complex food webs. Climate change can alter wetland extent and functions, but such impacts are unclear because there are multiple mechanistic pathways affecting inundation processes. Using a state-of-the-science Earth system model, future changes in wetland characteristics over North America are projected under two climate scenarios. At the continental scale, annual wetland area decreases by ~10% under the high emission scenario by the end of the century, whereas regional changes significantly vary, reaching ±50%. Wetland seasonality is projected to change drastically, with wetland areas shrinking in all seasons except winter. As the dominant driver of these changes shifts from precipitation to temperature in the higher emission scenario, wetlands undergo substantial drying during summer season when biotic processes peak. The projected disruptions to wetland cycles may therefore impact biodiversity of major wetland habitats in the upper Mississippi, Southeast Canada, and the Everglades in the future.