Form Submission: Participation Entry

Forest managers are faced with meeting a broad variety of societal demands such as wildlife habitat and aesthetic considerations while still providing monetary value to landowners through harvesting timber. Ecological forest management strategies such as irregular shelterwoods can offer alternatives to traditional forest management that help to meet these goals. These techniques often involve leaving more standing structure in the form of legacy trees, which allows less light to the forest floor, and thus often promotes growth of shade tolerant tree species over shade intolerant species. This study examines a 25-year chronosequence of 34 irregular shelterwoods designed to regenerate oak in southern New England. In each shelterwood we measured all legacy trees in a 50 m radius overstory plot, and measured seedling and sapling regeneration in 18 subplots. We focused on analyzing regeneration of the four most common species: red maple (Acer rubrum), black birch (Betula lenta), white pine (Pinus strobus), and red oak (Quercus rubra). We used ANOVA to compare the differences across age classes, both in total and relative growth, as well as to compare differences in regeneration growth based on variation in overstory basal area. Over time, regeneration followed known stand dynamics patterns, with self-thinning occurring in the regeneration of all focus species. Black birch thinned most drastically through time, and the saplings that survived retained a high position in the canopy. Red oak self-thinned most slowly, and by its third decade (19+ years since harvest), began to increase in growth rate above the other 3 species. As overstory basal area increased, growth of red oak slowed, with 5 m2/ha of overstory basal area as a limiting density. Resource managers should consider the tradeoff between increasing legacy trees and decreases in growth of oak regeneration, as well as long term effects of increased structure post-timber harvest.