Open AccessNitrogen addition, rather than altered precipitation, stimulates nitrous oxide emissions in an alpine steppe
Author(s) -
Yang Yang,
Xiao Yuanming,
Li Changbin,
Wang Bo,
Gao Yongheng,
Zhou Guoying
Publication year - 2021
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.8196
Subject(s) - precipitation , nitrous oxide , environmental science , abiotic component , nitrification , environmental chemistry , steppe , deposition (geology) , ecosystem , archaea , nitrogen cycle , biomass (ecology) , nitrogen , ecology , atmospheric sciences , chemistry , biology , sediment , geology , geography , paleontology , biochemistry , organic chemistry , meteorology , gene
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 2 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 −2 year −1 ) and altered precipitation (±50% precipitation) experiments was established in an alpine steppe of the QTP in 2013. Long‐term N addition significantly increased N 2 O emissions. However, neither long‐term alterations in precipitation nor the co‐occurrence of N addition and altered precipitation significantly affected N 2 O emissions. These unexpected findings indicate that N 2 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 2 O emissions. N 2 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 2 O emissions. Overall, this study provides pivotal insights to aid the prediction of future responses of N 2 O emissions to long‐term N deposition and precipitation changes in alpine ecosystems. The underlying microbial pathway and key predictors of N 2 O emissions identified in this study may also be used for future global‐scale model studies.