– by Josh Schlossberg, The Biomass Monitor
A recent study from the U.S. Forest Service’s (USFS) Rocky Mountain Research Station investigates the potential impacts on forest productivity from logging for biomass energy. While the study focuses primarily on the Northern Rockies region—where only a handful of small combined heat and power and biomass heating facilities operate—many of the findings may be applied to western forests.
The study, Impact of Biomass Harvesting on Forest Soil Productivity in the Northern Rocky Mountains, by Woongsoon Jang and Christopher Keyes from the University of Montana, and Deborah Page-Dumroese with the Rocky Mountain Research Station in Moscow, Idaho, assesses one of the main environmental concerns surrounding an expansion of bioenergy, the impact on forest soil productivity.
USFS defines forest productivity as the “integration of all environmental factors encompassing soil productivity, climate, topography, geology, vegetation, and the history of natural disturbances and anthropogenic interventions.” Ultimately, the question is whether logging for bioenergy may impair future forest growth.
Logging for bioenergy involves removing more organic matter from the forest than conventional logging for lumber alone. The practice of whole-tree logging extracts not just merchantable tree trunks for lumber, but also treetops, branches, and other logging byproducts, and has a “substantial impact on live vegetation,” according to study authors.
Though whole tree logging is not typically employed in the western U.S. forests, the authors predict that forests will “likely be managed more intensively in the future,” in part for biomass energy.