Published in:
Ecology and Evolution, 11 (2021) 21, Seite 15153-15163
Language:
English
DOI:
10.1002/ece3.8196
ISSN:
2045-7758
Origination:
Footnote:
Description:
<jats:title>Abstract</jats:title><jats:p>Anthropogenic‐driven global change, including changes in atmospheric nitrogen (N) deposition and precipitation patterns, is dramatically altering N cycling in soil. How long‐term N deposition, precipitation changes, and their interaction influence nitrous oxide (N<jats:sub>2</jats:sub>O) emissions remains unknown, especially in the alpine steppes of the Qinghai–Tibetan Plateau (QTP). To fill this knowledge gap, a platform of N addition (10 g m<jats:sup>−2</jats:sup> year<jats:sup>−1</jats:sup>) and altered precipitation (±50% precipitation) experiments was established in an alpine steppe of the QTP in 2013. Long‐term N addition significantly increased N<jats:sub>2</jats:sub>O emissions. However, neither long‐term alterations in precipitation nor the co‐occurrence of N addition and altered precipitation significantly affected N<jats:sub>2</jats:sub>O emissions. These unexpected findings indicate that N<jats:sub>2</jats:sub>O emissions are particularly susceptible to N deposition in the alpine steppes. Our results further indicated that both biotic and abiotic properties had significant effects on N<jats:sub>2</jats:sub>O emissions. N<jats:sub>2</jats:sub>O emissions occurred mainly due to nitrification, which was dominated by ammonia‐oxidizing bacteria, rather than ammonia‐oxidizing archaea. Furthermore, the alterations in belowground biomass and soil temperature induced by N addition modulated N<jats:sub>2</jats:sub>O emissions. Overall, this study provides pivotal insights to aid the prediction of future responses of N<jats:sub>2</jats:sub>O emissions to long‐term N deposition and precipitation changes in alpine ecosystems. The underlying microbial pathway and key predictors of N<jats:sub>2</jats:sub>O emissions identified in this study may also be used for future global‐scale model studies.</jats:p>