Silvicultural Prescriptions Affect Hardwood Tree Quality Over Five Decades of Management
A 50-year study by Forest Service scientists of data collected from the Fernow Experimental Forest (FEF) in West Virginia provided an opportunity to test for differences in the quality of trees harvested from three silvicultural practices. The harvest types are diameter-limit cutting, patch cutting, and single-tree selection. Harvest records from the years 1967 to 2013 include the butt log (the log taken from the base of a tree) grade for trees harvested from 18 compartments on the FEF. Cruise data from the mid-1980s was also available to assess residual stand quality in between harvests. The proportion of grade 1 butt logs was compared for each of the three harvest types over time. Researchers found that the diameter-limit proportion of grade 1 butt logs consistently decreases while patch cutting and single-tree selection proportions consistently increase for the period of record. While the proportions for each treatment differed significantly in the first 30-year period, at year 45 only the single-tree selection and diameter-limit proportions differed. Trends suggest that the proportion of grade 1 butt logs for each treatment is converging. Recent pre-harvest cruise data indicates that the diameter-limit harvests are not sustainable whereas the single-tree selection harvests are sustainable. Additional analysis is needed to assess the sustainability of patch cutting.