BER launches Environmental System Science Program. Visit our new website under construction!

U.S. Department of Energy Office of Biological and Environmental Research

BER Research Highlights

Increasing Impacts of Extreme Droughts on Vegetation Productivity Under Climate Change
Published: November 25, 2019
Posted: July 08, 2020

Multimodel analysis suggests increases in the frequency of extreme droughts and the magnitude of their effects on plant growth.

The Science
This research showed an increasingly stronger impact on terrestrial gross primary production (GPP) by extreme droughts than by mild and moderate droughts over the 21st century. Specifically, the percentage contribution by extreme droughts to the total GPP reduction associated with all droughts was projected to increase from ~28% during 1850–1999 to ~50% during 2075–2099.

The Impact
Even though higher carbon dioxide (CO2) concentrations in future decades can increase GPP, low soil water availability and disturbances associated with droughts could reduce the benefits of such CO2 fertilization. This study conducted the first global analysis to quantify potential impacts of drought on future GPP, an assessment which could guide future modeling and field experiments.

Terrestrial GPP is the basis of vegetation growth and food production globally and plays a critical role in regulating atmospheric CO2 through its impact on ecosystem carbon balance. In this study, scientists from the Next-Generation Ecosystem Experiments (NGEE)–Tropics project and Los Alamos National Laboratory (LANL) analyzed outputs of 13 Earth system models to show an increasingly stronger impact on GPP by extreme droughts than by mild and moderate droughts over the 21st century. The droughts were defined on the basis of root-weighted plant-accessible water. Due to a projected dramatic increase in the frequency of extreme droughts, the magnitude of globally averaged reductions in GPP associated with extreme droughts was projected to be nearly tripled by the last quarter of this century (2075–2099) relative to that of the historical period (1850–1999) under both high and intermediate greenhouse gas (GHG) emission scenarios. By contrast, the magnitude of GPP reductions associated with mild and moderate droughts was not projected to increase substantially. These drought impacts were widely distributed with particularly high risks for the Amazon, Southern Africa, Mediterranean Basin, Australia, and the southwestern United States. This analysis indicates a high risk of extreme droughts to the global carbon cycle with atmospheric warming; however, this risk can be potentially mitigated by positive anomalies of GPP associated with favorable environmental conditions.

BER Program Manager
Daniel Stover
U.S. Department of Energy Office of Science, Office of Biological and Environmental Research
Earth and Environmental Systems Sciences Division (SC-33.1)
Environmental System Science

Principal Investigator
Chonggang Xu
Los Alamos National Laboratory
Los Alamos, NM

This work was funded by (1) the Next-Generation Ecosystem Experiments (NGEE)–Tropics project and the Survival/Mortality project, both sponsored by the Terrestrial Ecosystem Science program of the U.S. Department of Energy’s (DOE) Office of Biological and Environmental Research within the DOE Office of Science; (2) the Laboratory Directed Research and Development program of Los Alamos National Laboratory; and (3) the University of California’s Laboratory Fees Research Program (Grant No. LFR-18-542511). Also used was the DOE Program for Climate Model Diagnosis and Intercomparison (PCMDI), which provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System (GOES) science portals.

Xu, C., N. G. McDowell, R. A. Fisher, L. Wei, S. Sevanto, E. Weng, and R. Middleton. “Increasing impacts of extreme droughts on vegetation productivity under climate change.” Nature Climate Change 9, 948–53 (2019). [DOI:10.1038/s41558-019-0630-6].

Related Links

Topic Areas:

  • Research Area: Earth and Environmental Systems Modeling
  • Research Area: Terrestrial Ecosystem Science
  • Research Area: Next-Generation Ecosystem Experiments (NGEE)

Division: SC-33.1 Earth and Environmental Sciences Division, BER


BER supports basic research and scientific user facilities to advance DOE missions in energy and environment. More about BER

Recent Highlights

Mar 23, 2021
Molecular Connections from Plants to Fungi to Ants
Lipids transfer energy and serve as an inter-kingdom communication tool in leaf-cutter ants&rsqu [more...]

Mar 19, 2021
Microbes Use Ancient Metabolism to Cycle Phosphorus
Microbial cycling of phosphorus through reduction-oxidation reactions is older and more widespre [more...]

Feb 22, 2021
Warming Soil Means Stronger Microbe Networks
Soil warming leads to more complex, larger, and more connected networks of microbes in those soi [more...]

Jan 27, 2021
Labeling the Thale Cress Metabolites
New data pipeline identifies metabolites following heavy isotope labeling.

Analysis [more...]

Aug 31, 2020
Novel Bacterial Clade Reveals Origin of Form I Rubisco

  • All plant biomass is sourced from the carbon-fixing enzyme Rub [more...]

List all highlights (possible long download time)