The Science

Key data on root distributions and soil water potential from prior Department of Energy–funded precipitation manipulations on the Oak Ridge Reservation (Tennessee) were used to illustrate mechanistic modeling needs. Results show challenges and opportunities associated with managing forests under conditions of increasing drought frequency and intensity and provide a belowground perspective on drought that may facilitate improved forest management.

The Impact

The study highlights how a belowground perspective of drought can be used in climate models to reduce uncertainty in predicting ecosystem consequences of droughts in forests.

Summary

Predicted increases in the frequency and intensity of droughts across the temperate biome have highlighted the need to examine the extent to which forests may differ in their sensitivity to water stress. At present, a rich body of literature exists on how leaf- and stem-level physiology influence tree drought responses. Less is known, however, regarding the dynamic interactions that occur belowground between roots and soil physical and biological factors. Consequently, better understanding is needed of how and why processes occurring belowground influence forest sensitivity to drought. This study reviews what is known about tree species’ belowground strategies for dealing with drought, and how physical and biological characteristics of soils interact with rooting strategies to influence forest sensitivity to drought. Findings show how a belowground perspective of drought can be used in models to reduce uncertainty in predicting ecosystem consequences of droughts in forests. Additionally, the researchers describe the challenges and opportunities associated with managing forests under conditions of increasing drought frequency and intensity and explain how a belowground perspective on drought may facilitate improved forest management.

Principal Investigator

Paul Hanson
Oak Ridge National Laboratory
hansonpj@ornl.gov

Program Manager

Daniel Stover
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
daniel.stover@science.doe.gov

Funding

The project is supported by the Office of Biological and Environmental Research, within the U.S. Department of Energy (DOE) Office of Science. Oak Ridge National Laboratory is managed by UT-Battelle, LLC, for DOE under Contract No. DE-AC05-00OR22725.

References