Researchers Investigate Impact of Biomass Harvest on Wildlife

by D'Lyn Ford (North Carolina State University/Biomass Magazine) On loblolly pine plantations in the Southeast, timber harvesting often involves an extra step: gleaning woody debris left behind after clearcutting. Branches, treetops and smaller trees are sources of biomass that can be compressed to make wood pellets, a renewable energy source often used for heating stoves and generating electricity.

Biomass harvesters may leave some of the woody debris on the ground to conserve food and cover for wildlife, but the guidelines they follow vary widely. Recommendations for the amount of debris to be left on the ground range from 10 to 30 percent, depending on the state. Some guidelines recommend creating piles of debris, while others say it should be left scattered across the land.

“We couldn’t determine what data the states were basing their biomass harvesting guidelines on,” says former NC State University doctoral student Sarah Fritts, lead author of studies published in the journals Ecological Applications and Forest Ecology and Management. “We thought it was important to track wildlife on sites that had used recommended operational practices in Georgia and North Carolina.”

Fritts spent four years counting mammals, reptiles and amphibians on clearcut loblolly plantation sites in Georgia and North Carolina.

She did in-depth research on how biomass harvesting affected populations of shrews, rodents, southern toads and eastern narrow-mouthed toads.

“We didn’t find significant differences in impact on wildlife based on biomass harvesting treatments, no matter how much biomass was removed following a clearcut or whether it was clustered or dispersed,” Fritts says. “The diversity, evenness and abundance of mammal, reptile and amphibian species generally were similar among all of the treatments.” READ MORE Abstract/Full Paper (Ecological Applications)