Managing forest land often generates lots of woody branches, pieces of trees and other loose woody material — slash in other words — from tree harvesting or thinning. While many landowners and managers look upon this material as a disposal dilemma, it also is a rich, and frequently overlooked, opportunity for to enhance wildlife habitat. Arranging slash materials into piles can provide birds, mammals and other wildlife in the forest with the food, water, space and cover they need.
Guidelines for piles
Here are a few best practices to build piles that attract and support desirable wildlife:
Quantity: As a target, try two piles per acre, about 100 feet apart, preferably in clusters of three to allow birds and small mammals to live in more than one pile. On smaller lots, perhaps one modest-sized pile will do. In dry country where fire is a concern, make sure that no piles are placed near structures or under trees where they could act as ladder fuels for fire.
Design: The goal is to create a long-lived structure with internal openings for wildlife to use. Therefore, larger material goes into the lowest layers forming the base while smaller material (such as small branches) goes over the top. You’ll also want the pile deep enough so provide wildlife secure cover in the middle of the pile.
Wood suspended above the ground dries out and rots more slowly than wood touching the moist ground so look for creative solutions, such as building around a log, stump, rock pile or other base structure (get creative and try using cinderblocks or other materials). This will provide a basis for the hollow core of the structure and help these spaces persist for a longer time as the wood decays.
If using small diameter logs from a tree thinning, place them in several triangular-shaped piles next to each other so as to create a tunnel-like structure (chipmunks love this). Use these piles as the base and proceed to put crisscrossing layers at least 3 to 5 feet deep above the base. More layers are better. Neatness is not necessary.
Top the structure with several layers of fine branches at least 18 inches deep. Green branches are generally ok, with one exception. Avoid using green ponderosa pine boughs between January and August to avoid creating a breeding ground for ips bark beetles. If you have large pieces of wood, allow them to dry out as much as possible before creating your pile. Once the pile is dry and established, risk from “bad bugs” is gone.
Construction: Working strictly by hand, make the piles up to 12-feet in diameter and up to 6-feet high, with enough material to provide a core that has openings for small animals to use for cover. This size can be constructed by hand, and will optimize the “edge effect” of the pile.
Smaller piles are fine, too. Consolidating branches into dense little teepees around stumps and logs can provide some cover for some small animal.
At DNR, our stewardship foresters help many landowners who have overstocked, dense stands of timber and are wondering what to do with all the material that will be produced by their thinning and harvesting projects. Saving a few of these piles, but burning, chipping or scattering the rest, is a great way to enhance wildlife habitat.
Get more tips about managing forestland in DNR’s free, quarterly e-newsletter Small Forest Landowner News
Take a deeper dive into forest management topics via Forest Stewardship Notes, a free quarter e-newsletter co-published by DNR and Washington State University Forestry Extension.