Consistent effects of nitrogen amendments on soil microbial communities and processes across biomes

Abstract Ecosystems worldwide are receiving increasing amounts of reactive nitrogen ( N ) via anthropogenic activities with the added N having potentially important impacts on microbially mediated belowground carbon dynamics. However, a comprehensive understanding of how elevated N availability affects soil microbial processes and community dynamics remains incomplete. The mechanisms responsible for the observed responses are poorly resolved and we do not know if soil microbial communities respond in a similar manner across ecosystems. We collected 28 soils from a broad range of ecosystems in N orth A merica, amended soils with inorganic N , and incubated the soils under controlled conditions for 1 year.…