文献类型： 外文期刊

作者： Yu, Yingchao ¹ ; Liu, Shuang ¹ ; Pan, Junxiao ¹ ; Zhu, Juntao ¹ ; Zong, Ning ¹ ; Zhang, Xinyuan ¹ ; Wu, Honghui ⁴ ; An, Hui ⁶ ; Diao, Huajie ⁷ ; Zuo, Xiaoan ⁸ ; Wei, Cunzheng ⁹ ; Zhang, Fawei ¹⁰ ; Yu, Qiang ¹¹ ; Zhang, Xinyu ¹ ;

作者机构： 1.Chinese Acad Sci, Inst Geog Sci & Nat Resources Res, Key Lab Ecosyst Network Observat & Modeling, Beijing, Peoples R China

2.Univ Chinese Acad Sci, Coll Resources & Environm, Beijing, Peoples R China

3.Natl Ecosyst Sci Data Ctr, Beijing, Peoples R China

4.Chinese Acad Agr Sci, Inst Agr Resources & Reg Planning, State Key Lab Efficient Utilizat Arable Land Chin, Beijing, Peoples R China

5.Chinese Acad Agr Sci, Inst Agr Resources & Reg Planning, Key Lab Plant Nutr & Fertilizer, Minist Agr & Rural Affairs, Beijing, Peoples R China

6.Ningxia Univ, Sch Ecol & Environm, Yinchuan, Peoples R China

7.Shanxi Agr Univ, Coll Grassland Sci, Taigu, Peoples R China

8.Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, State Key Lab Ecol Safety & Sustainable Dev Arid, Urat Desert Grassland Res Stn, Lanzhou, Peoples R China

9.Chinese Acad Sci, Inst Bot, State Key Lab Vegetat & Environm Change, Beijing, Peoples R China

10.Chinese Acad Sci, Northwest Inst Plateau Biol, Key Lab Adaptat & Evolut Plateau Biota, Xining, Peoples R China

11.Beijing Forestry Univ, Sch Grassland Sci, Beijing, Peoples R China

关键词： amino sugar; aridity index; China global change network; enzyme activity; increased precipitation; nitrogen; reduced precipitation

期刊名称：GLOBAL CHANGE BIOLOGY （ 影响因子：12.0； 五年影响因子：14.0 ）

ISSN： 1354-1013

年卷期： 2025 年 31 卷 7 期

页码：

收录情况： SCI

摘要： Soil microbial residue carbon (MRC) represents a significant component of soil carbon pools and regulates the response of soil carbon sequestration to precipitation changes. However, the response of soil MRC to extreme drought and wetness and the underlying mechanisms in regional grassland ecosystems remain unclear. Here, we quantified the responses of soil MRC content to extreme drought and wetness and identified the key drivers using a coordinated precipitation change experiment across nine alpine and temperate grassland ecosystems in China. Extreme drought (-50% precipitation) reduced MRC content by 8% on average. In contrast, extreme wetness (+50% precipitation) unexpectedly caused a pronounced 24% average decline in MRC content. Under extreme drought, reduced plant biomass inhibited soil MRC formation, and soil microbial N enzyme activity accelerated soil MRC decomposition. Moreover, wetter ecosystems exhibited greater losses of soil MRC, whereas drier ecosystems experienced a smaller decline. Under extreme wetness, increased soil microbial N enzyme activity accelerated the decomposition and utilization of microbial residue due to intensified microbial nitrogen limitation, resulting in a reduction in MRC. Our findings challenged the conventional understanding that extreme wetness promotes MRC accumulation by revealing a stronger reduction in MRC content under extreme wetness than under extreme drought. By uncovering distinct mechanisms driving MRC responses to extreme drought and wetness, our study provides critical insights into the dynamics of microbial-derived carbon in grassland ecosystems under future climate change.