Effects of Timber Harvesting and Biomass Removal on Forest Health Studied
Questions relating to how harvesting intensity and biomass removals affect the long-term ability of sites to sustain forest productivity is being studied across North America by a network of Forest Service scientists and their collaborators. This 10-year assessment of harvest effects shows that forest sites are able to experience high levels of soil compaction and biomass removal with little negative effects on seedling growth and nutrition.
The North American Long-term Soil Productivity (LTSP) Program was begun in the mid-1990s to quantify the short- and long-term effects of different intensities of timber harvesting and biomass removal on soil productivity at 29 different study sites located throughout North America, including the Missouri Carr Creek.
Recent examination of aboveground growth of planted trees and their foliar nitrogen and phosphorus concentrations showed that regional and transcontinental changes in planted tree biomass or foliar nutrition were neutral or positive with increasing intensity of harvesting disturbance and organic matter removal for most species after 10 years. Whole-tree harvesting or whole-tree plus forest-floor removal did not consistently reduce tree growth or foliar nutrients compared to stem-only harvest.
Soil compaction, including severe, consistently increased planted tree biomass at all study sites, if the forest floor was left intact. Vegetation control with herbicides consistently enhanced tree growth across all study sites and increased foliar nitrogen and phosphorus of pine and oak species. Overall, harvest-related organic matter removal and soil compaction did not result in large losses in stand biomass 10 years after harvesting, except for in aspen stands.
Forest Service Partners