Influence of Spatial Structure on Forest Growth and Stand Dynamics
NSRC researchers Aaron Weiskittel, Christian Kuehne, and Shawn Fraver examined effects of forest thinning treatments on forest stand and individual-tree growth and on changes in forest structure. Researchers also assessed how distance from forwarder (machinery that carries logs) trails influences individual-tree growth. They used measurements from six spruce-fir study locations across northern Maine that were not thinned until the study was initiated ten years ago. Thinning treatments included a non-thinned control and combinations of thinning method (low, dominant, or crown) and level of relative tree density reduction (33% or 50%). Researchers mapped tree stems and measured tree diameters annually for ten post-treatment years. Although high numbers of trees died in some of the thinned stands, tree growth rates in the low thinning treatments remained at relatively high levels throughout the study period. This suggests there is plenty of ongoing productivity potential in stands that were significantly less structurally modified by thinning. Full report available from nsrcforest.org.