Everything but the carbon sink: Cessation of N enrichment allows for rapid recovery of carbon cycling processes in a New England salt marsh

Abstract

Salt marshes provide critical ecosystem services, including storm protection, water filtration, wildlife habitat, and carbon sequestration. Nutrient pollution poses a major threat to these ecosystems as runoff from agricultural fields and wastewater systems delivers high loads of nitrogen and other nutrients. Several studies have shown that N enrichment alters carbon cycling processes in salt marshes, but there has been little work done to determine the capacity for recovery with reduction of N loading. Here we found that ecosystem respiration and decomposition processes returned to reference levels one year after cessation of nitrate addition in a chronically enriched Massachusetts salt marsh. Our results suggest that land management practices that reduce N loading in coastal systems may allow for rapid recovery of carbon cycling processes in enriched marshes.