Groundwater Buffers Impacts of Drought and Thinning in Southern Pine Forests
A long-term forest
hydrology monitoring study indicates that periodic severe drought or partial
tree thinning does not cause dramatic change in ecosystem water use and productivity.
Water shortage during drought is buffered by shallow groundwater storage while
thinning promotes water use by remaining trees and regrowth. Maintaining
groundwater is critical for intensive forest management under a changing
climate in the Atlantic lower coastal plain.
Pine plantations are a major economic component in the southern United
States representing the most intensively managed forests in the world. However,
the ecosystem services of these man-made forests are increasingly threatened by
climate change and other disturbances. Drought and forest thinning have the
potential to alter watershed water balances by reducing water use by trees and,
therefore, forest productivity. Eastern Forest Environmental Threat Assessment
Center researchers and partners used advanced techniques including instrumented
towers that collect atmospheric data and tree sapflow sensors to continuously
monitor forest water use in a loblolly pine plantation on the Atlantic lower
coastal plain for over a decade. Results from their study, published in the
journal Agricultural and Forest
Meteorology, suggest that severe drought and partial forest thinning had
limited impacts on seasonal and annual forest water use in this type of
ecosystem due to shallow groundwater that buffered soil water availability. These findings improve understanding of regional forest hydrological
processes and project potential effects of forest management and extreme
climate on forest water use and productivity.
Pictured: Loblolly pine plantations on the Atlantic lower coastal plain provide important
ecosystem services in the southern United States. Photo by USDA Forest Service.
Related publications:
External Partners/Collaborators: North Carolina State University
Contact: Ge Sun, Research Hydrologist, ge.sun@usda.gov
