Harvest

Harvesting is a term often used to describe the extraction of forest products from forested stands for monetary gain. Harvesting is also more often prescribed in order to regenerate a forest stand in a desirable fashion. There are several harvest methods that can be used to regenerate a stand with desirable species, while maintaining other values in the stand; for example wildlife, water quality, and aesthetics. Several factors affect the type of system used to create the desired future stand including the current stand type, age, and condition, as well as available equipment and forest product markets, soil conditions and depth, and exposure to wind.

Harvesting Methods:

Clear-cutting

This method is used when the desired future stand is an even-aged stand with uniform characteristics while minimizing site disturbance, and harvest costs. It involves the removal of all merchantable and often some non-merchantable material from the stand. It is useful on stands with any combination of low volume, high wind exposure, shallow soils, low value or short-lived species or trees, declining even-aged and over-mature stands.

Using this method means that buffers of 20 meters must be left on all streams and watercourses, and any harvest over 3 hectares has to have at least one wildlife clump consisting of trees representative of the stand that was removed. Variations of this include strip and patch cutting, and conversion cuts.

Shelter-wood Harvesting

Shelter-wood harvesting is another common variation on clear-cut harvesting where the over-story is removed in stages in order to help naturally regenerate a stand with species already present on the site. Each stage removes approximately 30-60 percent of the over-story, gradually increasing light to the forest floor while maintaining a seed source for regeneration. The final harvest removes the last of the over-story trees leaving a well established, even-aged stand similar in composition to the one that was harvested. This is often used when the present stand is made up of wind-firm trees of a shade tolerant species such as red or black spruce and white pine, or red oak, sugar maple, and yellow birch.

Selection Harvesting

This method is used to improve and manage an already wind-firm, uneven- aged stand of trees in good condition with adequate volume, canopy layers, and desired species. In this method, single trees or small groups of trees are removed from the mature age classes to regenerate new age classes, also trees are removed from intermediate age classes as a form of “stand tending” in order to “nurture” or improve their overall quality. This will result in regular entries into the stand at intervals of 5-20 years providing a regular flow of forest products, a general improvement in the quality of products removed from the stand over time. This can be combined with tree pruning in stands with qualifying species to produce knot free saw logs for higher value markets. Tree pruning and selection harvesting are both funded for qualifying stands through the Association for Sustainable Forestry: Category 7 program.