Thinning Timber for Wildlife

Thinning produces numerous timber and wildlife benefits. It improves the growth of the remaining trees and increases the amount of sunlight reaching the forest floor, stimulating the growth of a variety of herbs, forbs, legumes, and other herbaceous plants used by wildlife. The increased sunlight will also favor development of advanced regeneration of oaks and other species which do not grow well in shaded conditions. Thinnings increase the amount of available browse, primarily from the sprout growth of cut trees. It also produces temporary nesting cover from the tops of cut trees. It enables harvested trees to be utilized before they die naturally from competition. Finally, and of great importance to wildlife, it increases potential mast production (acorns, hickory nuts, etc.) as the crowns of the residual trees expand to fill the space once occupied by the harvested trees.

Beneficial wildlife habitat practices to include when doing a thinning are:

  1. Leave a variety of mast producers (oaks, hickory, gum, beech, etc.) as crop trees in the residual stand. By doing this, you decrease the possibility of having a complete mast failure. If one species or group of species does not produce mast in a particular year, there are other species that may be successful.
  2. Encourage grapevines in a stand whenever possible. Grapevines can be detrimental to quality timber production by breaking the tops and limbs out of trees, but they provide excellent food and cover for a variety of wildlife species. One grape arbor (1/4-1/2 ac) per 3 to 5 acres is good. Vertical and horizontal grape arbors offer two different types of cover. Vertical arbors can be encouraged by leaving standing trees with grapevines and felling adjacent trees into these trees to create a tepee effect. Horizontal arbors can be created by felling trees in a small area, where grapes are already present, and letting the grapevines grow in the limbs and branches on the ground.
  3. Leave wildlife cavity trees or den trees. Often times, these poorer quality trees are ones you would consider removing to allow better quality trees to grow; however, these trees provide critical habitat for cavity nesting birds and mammals, such as squirrels, raccoons, owls, woodpeckers, etc. Some poorer quality trees that have the potential to develop into cavity trees should be left if den trees are not prevalent. Leave a minimum of 2 to 4 cavity trees per acre. In addition, leave some dead snags in the stands for perch trees and to provide possible feeding sites for insect foraging birds and mammals.
  4. Leave an abundant supply of soft mast producers in the stand, especially dogwoods, serviceberry, blackgum, hawthorn, crabapple, etc., to provide an additional food source.
  5. Stabilize all haul roads, skid trails, and log landings with a grass mixture which is beneficial to wildlife. This will create additional habitat for grazing animals, such as rabbits and deer, plus will serve as insect foraging areas for songbirds, grouse, and turkey chicks. Fescue should be avoided, except for the most steep areas, since it is detrimental to wildlife.
  6. Protect spring seeps. They provide valuable feeding areas for wildlife during winter when the countryside is frozen or snowcovered. These areas are heavily utilized by wildlife, especially turkeys. They should be buffered by at least 100 feet from timber harvesting on each side of the seep.
  7. Create waterholes where suitable sites exist by excavating small depressions in areas that would tend to catch water during rainy periods. Available water is a critical habitat factor for wildlife, especially in late summer and early fall. These are particularly important high up on the mountains or on the upper slopes.
  8. Protect old homesites and abandoned orchards as they provide unique habitats and usually contain a wide variety of plant life, including fruit trees and shrubs, and are heavily utilized by wildlife. Fruit trees should be released and/or pruned to encourage increased fruit production.