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Interactive global change factors mitigate soil aggregation and carbon change in a semi‐arid grassland
Author(s) -
Bai Tongshuo,
Wang Peng,
Hall Steven J.,
Wang Fuwei,
Ye Chenglong,
Li Zhen,
Li Shijie,
Zhou Luyao,
Qiu Yunpeng,
Guo Jiuxin,
Guo Hui,
Wang Yi,
Hu Shuijin
Publication year - 2020
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.15220
Subject(s) - environmental science , soil carbon , grassland , arid , global change , precipitation , global warming , climate change , agronomy , biomass (ecology) , soil respiration , soil water , soil science , ecology , biology , geography , meteorology
The ongoing global change is multi‐faceted, but the interactive effects of multiple drivers on the persistence of soil carbon (C) are poorly understood. We examined the effects of warming, reactive nitrogen (N) inputs (12 g N m −2 year −1 ) and altered precipitation (+ or − 30% ambient) on soil aggregates and mineral‐associated C in a 4 year manipulation experiment with a semi‐arid grassland on China's Loess Plateau. Our results showed that in the absence of N inputs, precipitation additions significantly enhanced soil aggregation and promoted the coupling between aggregation and both soil fungal biomass and exchangeable Mg 2+ . However, N inputs negated the promotional effects of increased precipitation, mainly through suppressing fungal growth and altering soil pH and clay‐Mg 2+ ‐OC bridging. Warming increased C content in the mineral‐associated fraction, likely by increasing inputs of root‐derived C, and reducing turnover of existing mineral‐associated C due to suppression of fungal growth and soil respiration. Together, our results provide new insights into the potential mechanisms through which multiple global change factors control soil C persistence in arid and semi‐arid grasslands. These findings suggest that the interactive effects among global change factors should be incorporated to predict the soil C dynamics under future global change scenarios.