Increasing sensitivity of dryland vegetation greenness to precipitation due to rising atmospheric CO2

Yao Zhang; Pierre Gentine; Xiangzhong Luo; Xu Lian; Yanlan Liu; Sha Zhou; Anna M Michalak; Wu Sun; Joshua B Fisher; Shilong Piao; Trevor F Keenan

doi:10.1038/s41467-022-32631-3

Increasing sensitivity of dryland vegetation greenness to precipitation due to rising atmospheric CO₂

Nat Commun. 2022 Aug 19;13(1):4875. doi: 10.1038/s41467-022-32631-3.

Authors

Yao Zhang^{1

2

3}, Pierre Gentine⁴, Xiangzhong Luo⁵, Xu Lian^{6

4}, Yanlan Liu⁷, Sha Zhou⁸, Anna M Michalak⁹, Wu Sun⁹, Joshua B Fisher¹⁰, Shilong Piao^{6

11}, Trevor F Keenan^{12

13}

Affiliations

¹ Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China. zhangyao@pku.edu.cn.
² Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. zhangyao@pku.edu.cn.
³ Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, USA. zhangyao@pku.edu.cn.
⁴ Department of Earth and Environmental Engineering, Columbia University, New York, NY, USA.
⁵ Department of Geography, National University of Singapore, Singapore, Singapore.
⁶ Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing, China.
⁷ School of Earth Sciences, The Ohio State University, Columbus, OH, USA.
⁸ State Key Laboratory of Earth Surface Processes and Resources Ecology, Faculty of Geographical Science, Beijing Normal University, Beijing, China.
⁹ Department of Global Ecology, Carnegie Institution for Science, Stanford, CA, USA.
¹⁰ Schmid College of Science and Technology, Chapman University, Orange, CA, USA.
¹¹ State Key Laboratory of Tibetan Plateau Earth System, Resources and Environment, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, China.
¹² Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. trevorkeenan@berkeley.edu.
¹³ Department of Environmental Science, Policy and Management, UC Berkeley, Berkeley, CA, USA. trevorkeenan@berkeley.edu.

Abstract

Water availability plays a critical role in shaping terrestrial ecosystems, particularly in low- and mid-latitude regions. The sensitivity of vegetation growth to precipitation strongly regulates global vegetation dynamics and their responses to drought, yet sensitivity changes in response to climate change remain poorly understood. Here we use long-term satellite observations combined with a dynamic statistical learning approach to examine changes in the sensitivity of vegetation greenness to precipitation over the past four decades. We observe a robust increase in precipitation sensitivity (0.624% yr^-1) for drylands, and a decrease (-0.618% yr^-1) for wet regions. Using model simulations, we show that the contrasting trends between dry and wet regions are caused by elevated atmospheric CO₂ (eCO₂). eCO₂ universally decreases the precipitation sensitivity by reducing leaf-level transpiration, particularly in wet regions. However, in drylands, this leaf-level transpiration reduction is overridden at the canopy scale by a large proportional increase in leaf area. The increased sensitivity for global drylands implies a potential decrease in ecosystem stability and greater impacts of droughts in these vulnerable ecosystems under continued global change.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

Carbon Dioxide*
Climate Change
Droughts
Ecosystem*
Water

Substances

Water
Carbon Dioxide

Associated data

figshare/10.6084/m9.figshare.7504448.v3