Precipitation threshold-driven shifts in dominant controls of ecosystem nitrogen retention (opens in new tab)

Ecosystem nitrogen retention results from complex, long-term plant–soil–microbe interactions, yet integrating these processes across climatic gradient remains challenging. As a time-integrated tracer, the natural abundance of the stable nitrogen isotope (δ15N) in soil captures the cumulative balance of nitrogen inputs, transformations and losses, offering a robust proxy for ecosystem nitrogen retention. Although spatial patterns in δ15N have been widely documented, the drivers and their shift...