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

BER Research Highlights

Physiologically-Linked Indices of Rainfall Variation Predict Water Stress For Central U.S. Tree Species
Published: December 11, 2015
Posted: May 02, 2016

Multiyear measurements enable researchers to predict impacts of precipitation regimes on central U.S. deciduous forest trees.

The Science
Long-term measurements at an AmeriFlux site in Missouri have enabled researchers to understand and predict how precipitation regimes affect water stress levels for key plant species in a central U.S. deciduous forest.

The Impact
How precipitation regimes affect water stress levels for plant species with contrasting water use strategies is not well understood. This study establishes a simple approach to quantifying plant physiological drought and the ecological impacts of precipitation regimes. This approach will be useful in predictions of forest response to climate change.

Variations in precipitation regimes can shift ecosystem structure and function by altering frequency, severity, and timing of plant water stress. Being able to predictively understand impacts of precipitation regimes on plant water stress is crucial in a changing climate. The research team, led by Oak Ridge National Laboratory (ORNL), formulated complementary, physiologically-linked indices of precipitation variability (PV) and related them to continuous measurements of predawn leaf water potential—a fundamental indicator of plant water status—in six tree species with different water use strategies in a central U.S. forest. These indices explained nearly all interannual variations in water stress levels for all species. These species differed in sensitivities to variations in precipitation regimes with the differences more pronounced in response to PV than to amount. Further, they exhibited stress tradeoffs between low and high PV, suggesting that how different plant species respond to PV is part of species-specific water use strategies in a plant community facing the uncertainty of fluctuating precipitation regimes. The new indices provide simple ways to quantify physiological drought and the ecological impacts of precipitation regimes in a changing climate.


Daniel Stover, SC-23.1, daniel.stover@science.doe.gov, 301-903-0289; and Jared DeForest, SC-23.1, jared.deforest@science.doe.gov, 301-903-1678

(PI Contact)
Lianhong Gu
Environmental Sciences Division and Climate Change Science Institute, ORNL
lianhong-gu@ornl.gov, 865-241-5925

This work was supported by the U.S. Department of Energy (DOE), Office of Science, Office of Biological and Environmental Research, Climate and Environmental Sciences Division. ORNL is managed by the University of Tennessee (UT)-Battelle, LLC, for DOE under contract DE-AC05-00OR22725.

Gu, L., S. G. Pallardy, K. P. Hosman, and Y. Sun. 2016. “Impacts of Precipitation Variability on Plant Species and Community Water Stress in a Temperate Deciduous Forest in the Central US,” Agricultural and Forest Meteorology 217, 120–36. DOI: 10.1016/j.agrformet.2015.11.014. (Reference link)

Topic Areas:

  • Research Area: Earth and Environment Systems Data Management
  • Research Area: Terrestrial Ecosystem Science

Division: SC-23.1 Climate 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

May 10, 2019
Quantifying Decision Uncertainty in Water Management via a Coupled Agent-Based Model
Considering risk perception can improve the representation of human decision-making processes in age [more...]

May 09, 2019
Projecting Global Urban Area Growth Through 2100 Based on Historical Time Series Data and Future Scenarios
Study provides country-specific urban area growth models and the first dataset on country-level urba [more...]

May 05, 2019
Calibrating Building Energy Demand Models to Refine Long-Term Energy Planning
A new, flexible calibration approach improved model accuracy in capturing year-to-year changes in bu [more...]

May 03, 2019
Calibration and Uncertainty Analysis of Demeter for Better Downscaling of Global Land Use and Land Cover Projections
Researchers improved the Demeter model’s performance by calibrating key parameters and establi [more...]

Apr 22, 2019
Representation of U.S. Warm Temperature Extremes in Global Climate Model Ensembles
Representation of warm temperature events varies considerably among global climate models, which has [more...]

List all highlights (possible long download time)