U.S. Forest Service Southern Research Station (SRS) Coweeta Hydrologic Laboratory (Coweeta) scientists and collaborators recently received a $972,000 grant from the USDA Agriculture and Food Research Initiative (AFRI) to study water use in loblolly pine—the most commercially important tree species in the southeastern U.S. and the primary candidate for woody bioenergy production in the region—and eucalyptus—an emerging bioenergy species exhibiting great production potential.
Industrial and private landowners routinely grow native loblolly pine for timber, and the species is now grown in some areas as a bioenergy crop. Trees grown for bioenergy are grown in shorter rotation cycles than timber, and the more intensive management for bioenergy crops has raised concern about water use, especially in the case of eucalyptus.
To compare water use and the impact on Coastal Plain hydrology of the two species, Coweeta scientists will install bioenergy plots of loblolly pine and eucalyptus at the Savannah River Site in South Carolina, where SRS researchers conduct a wide range of studies in collaboration with U.S. Department of Energy scientists and others.
“We will grow these species side-by-side under intensive management to compare water use and determine actual water sources for these crops,” says Chelcy Miniat, project leader for the SRS Center for Forest Watershed Research and investigator for the project. “We’ll plant both species along a gradient of depth to groundwater to look at the source of water they use, whether it’s groundwater or soil water. We’ll also determine the total amount of water used for each species over several years of the full-rotation, and use mechanistic models to scale in space and time.”
The results will be used to help develop a model to predict the effects of high production planting on local and regional hydrology. “The data we collect from these side-by-side comparisons are critically needed to determine the impact of woody bioenergy crops on surface water supplies in the Southeast,” says Miniat.
In addition to Miniat, investigators include SRS research hydrologist Pete Caldwell (now at Coweeta), Rhett Jackson (University of Georgia), Jeff McDonnell (University of Saskatchewan), and Doug Aubrey (Georgia Southern University).
The study will be conducted in cooperation with the Forest Service at the Savannah River Site, and with MeadWestvaco, which will provide eucalyptus seedlings and cultural expertise.
For more information, email Chelcy Miniat at email@example.com.