Global variations in critical drought thresholds that impact vegetation

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Xiangyi Li - , Peking University (Author)
  • Shilong Piao - , Peking University, CAS - Institute of Tibetan Plateau Research (Author)
  • Chris Huntingford - , Centre for Ecology and Hydrology (Author)
  • Josep Peñuelas - , CREAF - Centre for Ecological Research and Forestry Applications (Author)
  • Hui Yang - , Peking University, Max Planck Institute for Biogeochemistry (Author)
  • Hao Xu - , Peking University (Author)
  • Anping Chen - , Colorado State University (Author)
  • Pierre Friedlingstein - , University of Exeter, Ecole Normale Superieure (Author)
  • Trevor F. Keenan - , Lawrence Berkeley National Laboratory, University of California at Berkeley (Author)
  • Stephen Sitch - , University of Exeter (Author)
  • Xuhui Wang - , Peking University (Author)
  • Jakob Zscheischler - , Helmholtz Centre for Environmental Research (Author)
  • Miguel D. Mahecha - , Leipzig University (Author)

Abstract

Identifying the thresholds of drought that, if crossed, suppress vegetation functioning is vital for accurate quantification of how land ecosystems respond to climate variability and change. We present a globally applicable framework to identify drought thresholds for vegetation responses to different levels of known soil-moisture deficits using four remotely sensed vegetation proxies spanning 2001–2018. The thresholds identified represent critical inflection points for changing vegetation responses from highly resistant to highly vulnerable in response to drought stress, and as a warning signal for substantial vegetation impacts. Drought thresholds varied geographically, with much lower percentiles of soil-moisture anomalies in vegetated areas covered by more forests, corresponding to a comparably stronger capacity to mitigate soil water deficit stress in forested ecosystems. Generally, those lower thresholds are detected in more humid climates. State-of-the-art land models, however, overestimated thresholds of soil moisture (i.e. overestimating drought impacts), especially in more humid areas with higher forest covers and arid areas with few forest covers. Based on climate model projections, we predict that the risk of vegetation damage will increase by the end of the twenty-first century in some hotspots like East Asia, Europe, Amazon, southern Australia and eastern and southern Africa. Our data-based results will inform projections on future drought impacts on terrestrial ecosystems and provide an effective tool for drought management.

Details

Original languageEnglish
Article numbernwad049
JournalNational science review
Volume10
Issue number5
Publication statusPublished - 1 May 2023
Peer-reviewedYes
Externally publishedYes

Keywords

ASJC Scopus subject areas

Keywords

  • drought impacts, drought threshold, inflection points, soil moisture, vegetation response