Contrasting Silvicultural Systems

Research Issue

Silviculture is defined by the Society of American Foresters as "the art and science of controlling the establishment, growth, composition, health, and quality of forests and woodlands to meet the diverse needs and values of landowners and society on a sustainable basis." In order to provide science-based guidance to society and landowners to support their silvicultural decisions, scientists must implement replicated examples of different silvicultural treatments and assess their outcomes. Such research often requires decades of measurements, and outcomes and outputs vary by forest type and ecoregion. Results can also be complicated by interactions among silvicultural systems and treatments and other landscape scale disturbances

Our Research

In 1980, John Bjorkbom installed a long-term study to contrast stand development under 5 different silvicultural systems through the course of a full rotation. The study was installed on the Kane Experimental Forest in 1980 with a plan to run through 2060. The study contrasts stand development in even-age systems with shelterwood regeneration method, two-age systems with shelterwood regeneration method, single-tree selection system, group selection system, and an economic selection system that includes harvest of only sawtimber-sized trees. All trees 1.0" and larger are tallied every 5 years, and 6-foot radius regeneration sample plots are also tallied by species and height class on the same interval. Treatment plots are 4.9 acre squares, and there have been two cutting cycles in the study area.

Expected Outcomes

The study is designed to allow a comprehensive comparison of stand development, productivity, and yield over a full even-age rotation.  At each cutting cycle, one of the four replications in the even-age system is regenerated, so that by the end of the study period, the four plots will represent a balanced forest.  Similarly, two of the two-age plots were harvested at the beginning of the study, and two more will be harvested at the mid-point of the study.  Interactions of silvicultural system with sugar maple decline, beech bark disease, and white-tailed deer impacts complicate analyses but enrich the potential information to be gathered from the study. 

Research Results

Stout, Susan L.  1994. Silvicultural systems and stand dynamics in Allegheny hardwoods. New Haven, CT: Yale, Univ. D.F. Dissertation.

Research Participants

Principal Investigator

• Susan Stout, USDA Forest Service- Northern Research Station Project Leader/Research Forester

Research Partner

• Allegheny National Forest

For further information log on website :
http://www.nrs.fs.fed.us/sustaining_forests/conserve_enhance/timber/herbicides/