Sustaining Tree Quality Under Three Harvesting Methods
In the practice of silviculture, foresters manage forest characteristics for a variety of resource objectives. While timber is often of interest, other objectives include wildlife, clean water, or recreation. For all of these, sustainability can be interwoven as an additional objective. Long-term studies on the Fernow Experimental Forest in West Virginia have addressed several of these objectives. Forest Service scientists examined harvest records from nearly 50 years on three types of cutting practices, diameter-limit cutting, patch cutting, and single-tree selection, to compare tree quality. They found that the percentage of cut grade one trees at harvest is significantly different among the three cutting practices at the 15- and 30-year marks in the study, with the diameter limit percentages exceeding those in both the patch cutting and single tree selection practices. However at year 45, analysis showed that the diameter limit harvest percentages were not different than the patch cutting, nor the patch cutting from the single tree selection. More importantly, the long-term trajectory of the percentage of cut grade one trees from the diameter limit cuts was decreasing, while the trajectory of this percentage for the patch cutting and single tree selection practices was increasing. This is evidence that diameter limit cutting is not sustainable over the long term.