Details

Autor(en) / Beteiligte

• 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

Titel

Interactive global change factors mitigate soil aggregation and carbon change in a semi‐arid grassland

Ist Teil von

• Global change biology, 2020-09, Vol.26 (9), p.5320-5332

Ort / Verlag

England: Blackwell Publishing Ltd

Erscheinungsjahr

2020

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• 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 Mg2+. However, N inputs negated the promotional effects of increased precipitation, mainly through suppressing fungal growth and altering soil pH and clay‐Mg2+‐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. Interactive global change factors (warming, precipitation alteration and nitrogen [N] deposition/inputs) affected soil aggregation and persistence of soil carbon (C) through modifying both biological and geochemical processes. In the absence of N inputs, precipitation increase promotes soil aggregation through increasing soil exchangeable Mg2+ (geochemical process) and promoting fungal growth (biological process). However, N inputs negated the promotional effects of increased precipitation, mainly through suppressing fungal growth and altering soil pH and clay‐Mg2+‐OC bridging.