Vertical root distribution underpins belowground resistance to extreme drought
Abstract Extreme droughts are becoming more frequent and strongly affect ecosystem productivity, yet their impact on belowground productivity—key to the carbon cycle—remain underexplored. Using a coordinated drought experiment across six Eurasian grassland sites spanning a precipitation gradient, we found that extreme drought had little effect on belowground net primary productivity (BNPP) or root biomass across the 0-20 cm soil profile because drought-induced shifts in root allocation compensated across soil depths. Specifically, drought induced site- and depth-specific shifts: in xeric grasslands, BNPP and root biomass increased in the 0-10 cm layer but declined in the 10-20 cm layer, whereas mesic grasslands exhibited the opposite pattern. These contrasting responses were consistent with shifts in depth-specific soil moisture. Consequently, the apparent resistance of belowground productivity to drought masks a redistribution of root growth along the vertical soil profile. Accounting for such depth-dependent root dynamics is essential for understanding ecosystem functioning, including carbon cycling, plant persistence, and ecosystem responses to intensifying climate extremes.
Authors
- Melinda D. Smith (ORCID: https://orcid.org/0000-0003-4920-6985)
- Iain P. Hartley (ORCID: https://orcid.org/0000-0002-9183-6617)
- Wentao Luo (ORCID: https://orcid.org/0000-0002-9543-1123)
- Chong Xu (ORCID: https://orcid.org/0000-0001-7438-8325)
- Yingjie Yan (ORCID: https://orcid.org/0000-0003-0659-5503)
- Ingrid J. Slette (ORCID: https://orcid.org/0000-0002-7707-3246)
- Wenping Yuan (ORCID: https://orcid.org/0000-0002-1469-4395)
- Yuguang Ke (ORCID: https://orcid.org/0000-0002-1884-7627)
- Yann Hautier (ORCID: https://orcid.org/0000-0003-4347-7741)
- Wei Zhou (ORCID: https://orcid.org/0000-0001-9508-3598)
- Tian Yang (ORCID: https://orcid.org/0000-0002-9667-1989)
- Deliang Kong
- Hongqiang Wang
- Wenju Zhang
- Honghui Wu
- Shikui Dong
- Xiaoping Xin
- Minggang Xu
- Liebao Han
- Baoming Ji
- Yadong Yang
- Jiale Chen
- Xingguo Han
- Xiaoan Zuo
- Qiang Yu
- Guirui Yu
- Yunlong Zhang
- Elizabeth T Borer
Institutions
- Shanxi Agricultural University (CN)
- Western University (CA)
- University of Minnesota (US)
- Shanxi University (CN)
- Utrecht University (NL)
- Chinese Academy of Sciences (CN)
- Peking University (CN)
- University of Exeter (GB)
- Beijing Botanical Garden (CN)
- Beijing Forestry University (CN)
- Northwest Institute of Eco-Environment and Resources (CN)
- Institute of Agricultural Resources and Regional Planning (CN)
- Institute of Applied Ecology (CN)
- Institute of Grassland Research (CN)
- Institute of Geographic Sciences and Natural Resources Research (CN)
- Hebei University (CN)
- Henan Agricultural University (CN)
- China Agricultural University (CN)
- Colorado State University (US)
Publication Details
- Journal
- National Science Review
- Published
- 2026-09-15
- DOI
- https://doi.org/10.1093/nsr/nwag592
- Primary Topic
- Plant Water Relations and Carbon Dynamics
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- Inner Mongolia Agricultural University