Uneven Aged Management

When trees in a forest stand have a range of ages from young to old, the stand is called uneven-aged.  When forest landowners manage their forests by selectively removing individual trees and replanting seedlings, their approach is known as uneven-aged management. This is opposed to even-aged management where all of the trees have the same age, and they are all harvested at the same time.

A balanced uneven-aged stand looks like an undisturbed, old-growth forest. As older individual trees die, seedlings which have been struggling in the understory shoot up to fill the canopy. Uneven-aged management methods were developed to try to duplicate the natural replacement of trees in old-growth forests.

Crop trees are selected as the desired oldest generation. The trees around them are eliminated to open up some of the canopy for understory trees and to allow the crop trees to reach their potential. In other areas of the Managed Forest, all of the older trees of less desirable species may be sacrificed; this exposes seedlings to the sunlight and emphasizes the forest's younger generations.

Since forests tend to evolve to a mature, or climax, stage with a dense canopy until some disturbance opens it up, uneven-aged management requires a little more attention than even-aged methods. Uneven-aged management continually tries to keep the forest from reaching climax stage through thinning, crop tree release, and small areas of regeneration.

If this management method is performed well, the forest remains healthy and vigorous. Diseased trees are thinned out; the better trees are favored; the nut and seed producers are encouraged. The disadvantages of this method is that harvesting individual trees is difficult, frequently causing damage to live trees. Most everything about forestry is a compromise.