Impacts of Timber and Biomass Harvesting on Soil Biological Quality
The Long-Term Soil Productivity Study was conceived a quarter-century ago by a consortium of U.S. and Canadian scientists. Recognizing that properly functioning soil is a prerequisite for the health of forested ecosystems, the scientists installed a common experiment at more than 60 sites to test the resilience of soils and forests following moderate-to-severe disturbance. Treatments included several levels of soil compaction in combination with partial or complete removal of nutrient-rich surface organic residues. The premise in the current research was that changes in soil microbial community diversity and root proliferation are common following harvest disturbance, yet the extent of change is tempered using responsible and commonly employed practices. Bacterial and fungal diversity was measured using metagenomics techniques, and rooting profiles were examined in large exposed trenches. Coarse-scale microbial diversity differed among soils across the two countries, but was generally similar within each study location, regardless of disturbance treatments. Fine-scale diversity was affected primarily by the complete removal of surface organics (scalping) which modified soil temperature and moisture regimes. In contrast, root proliferation showed an unexpected tolerance to severe compaction after two decades of forest development. These findings confirm that upland forest soil functioning remains robust following a one-time harvest disturbance.
Forest Service Partners