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

BER Research Highlights


Changing Water Balance in Forests Exposed to Elevated CO2
Published: April 18, 2011
Posted: April 29, 2011

Plants influence ecosystem water balance through responses to environmental conditions, and their sensitivity to climate change could alter the ecohydrology of future forests. DOE scientists at Oak Ridge National Laboratory used a combination of measurements, synthesis of existing literature, and modeling to study the consequences of elevated CO2 on ecohydrologic processes in forests. Data from five of DOE’s free-air CO2 enrichment (FACE) sites reveal that elevated CO2 reduced the passage of water vapor through the stomata, or small pores of the plant, leading to declines in canopy transpiration and water use for three closed-canopy forest sites. At the sweetgum FACE experiment in Oak Ridge, Tennessee, elevated CO2 reduced seasonal transpiration by 10–16%. Model simulations also predicted reduced demand for water in response to elevated CO2. The direct effect of elevated CO2 on forest water balance through reductions in transpiration could be considerable, especially following canopy closure and development of maximal leaf area index. Complementary, indirect effects of elevated CO2 include potential increases in root or leaf litter and soil organic matter, shifts in root distribution and altered patterns of water extraction.

References: Warren, J. M., E. Pötzelsberger, S. D. Wullschleger, P. E. Thornton, H. Hasenauer, and R. J. Norby. 2011. “Ecohydrologic Impact of Reduced Stomatal Conductance in Forests Exposed to Elevated CO2,” Ecohydrology 4, 196–210. DOI: 10.1002/eco.173.

Contact: Mike Kuperberg, SC-23.1, (301) 903-3281, Daniel Stover, SC-23.1, (301) 903-0289
Topic Areas:

  • Research Area: Terrestrial Ecosystem Science
  • Research Area: Carbon Cycle, Nutrient Cycling
  • Research Area: Free Air CO2 Enrichment (FACE)

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)