How Tree "Neighborhood" Structure Affects Growth and Regeneration in Oak-Pine Forests

Oak-pine stands are an important part of the forest resource in the Northeast and cover almost 1.5 million acres in Maine alone. These lands have high recreational, wildlife habitat, and commodity values but tend to be on small parcels often subject to irregular partial cutting or high-grading. Oak-pine stands are likely to continue to provide a source of quality pine sawtimber and valuable hardwood in the future, but relatively little is known about their productivity. They typically contain many tree species, although northern red oak, eastern white pine, red maple, and eastern hemlock are usually the most abundant. Because they contain a number of species, complex structures develop within oak-pine stands.

The microenvironment surrounding each tree in a stand is modified by the characteristics of its neighbors, so there can be great environmental variation within mixed stands. Neighborhood structure can vary within stands which may effect growth and development. Understanding the influences of neighborhood-scale structure may improve growth prediction and refine silvicultural treatments. Effective management of oak-pine stands on small parcels may require a better understanding of neighborhood-scale processes.

The goal of this project is to determine how growth and advance regeneration are affected by different neighborhood-scale arrangements of trees in northern red oak-eastern white pine stands. NSRC researchers will test how: 1) growth per unit area will differ among categories of neighborhood-scale structure; 2) growth and yield of individual oak and pine trees will vary according to the neighborhood types they occupy; and 3) the composition and growth rate of advance regeneration will differ beneath different neighborhood types.