Timber Stand Improvements

by? Michael Foster?? Associate Consultant Davey Resource Group

The focus of this article is on a particular management practice that can aid small acreage? landowners in improving the quality of the timber on their property, while simultaneously bolstering the wildlife habitat on their properties. The practice I am referring to is? Timber Stand Improvement (TSI). While timber harvesting and TSI are often considered two? different forest management activities, they are not necessarily mutually exclusive of one? another.??

A forested stand with fewer quality trees is often healthier than a forested stand with a greater? density due to a lack of competition. Furthermore, less dense forested stands where sunlight can? reach the forest floor tend to have greater wildlife diversity due to the increased vegetative? growth in the understory. As a management practice can be thought of as weeding or pruning? away unwanted vegetation. TSI is the periodic felling—or killing through girdling and herbicide? treatment—of immature, subdominant, undesirable, and crowded trees to stimulate understory? growth and provide more resources for dominant, well formed, and mast producing trees, thus? releasing them from competition and improving the overall health of the stand.?

When engaging in a TSI project low value and undesirable trees should be focused on first.? Hardwood species like sweetgum, tulip poplar, red maple, sourwood, birch, and sycamores are? often of low wildlife and commercial value and make easily identifiable targets at the beginning? of TSI efforts. These trees are often shade intolerant species—with some exception—that? established early in the successional progression of a particular forested stand and are often the? dominant trees in a stand, having large canopies that prevent sunlight from reaching the forest? floor.?

Thinning projects are not limited to low value trees. Subdominant, suppressed, or overtopped? trees and crowded trees are next on the list. Overtopped trees receive little light because they are? often growing in the shadow of dominant or codominant individuals. In many cases these trees? can be the same age as their dominant counterparts; however, they are much smaller in size? because they are poor growers. Even with the release from competition that removing a larger,? undesirable tree provides, suppressed trees usually will not become a valuable tree and for the? health of the stand it should be removed. Crowded trees—e.g. trees growing too closely? together—compete for resources and prevent one another from spreading their branches and? maximizing their mast producing potential. In these cases, choose those individuals with the best? growth form to save and remove the rest.

Aside from the increased forage availability created by allowing sunlight to reach the forest? floor, TSI can create vertical structure, cover value, and snag habitat. Large, dominant low? valued trees are often not felled in a TSI situation due to the potential damage felling them may? cause to desirable trees. These trees are often girdled and the wound is squirted with an imazapyr? or triclopyr based herbicide during the late summer to early fall portion of the year to completely? kill the root system. The tree is left standing creating a snag that can be used by many wildlife? species as nesting/denning cover. Once these trees have fallen their benefits do not end. At this? point they provide quality habitat for salamanders and lizards, detritivores, and small mammals? like skunks and raccoons. Brush and bramble that often grow on the forest floor not only provide? forage value but it is an excellent source of cover for a variety of small mammals and birds.??

Timber Stand Improvement can be a great tool for the small acreage landowner; especially if? they do not possess heavy equipment. It can be done using a hatchet, chainsaw, and a measured? squirt bottle.?