Woodland owners seem to have a lot to worry about these days. Threats to the health of their woodlands are announced regularly as new insects or diseases are detected, drought rages, or invasive plant species compete with native vegetation. Some threats, like the emerald ash borer or a large tornado, can result in nearly unstoppable destruction. However, there are some actions woodland owners can take to make their woodlands more resistant to other damaging agents or events. One of the best preventative measures is to use forest management practices to make the trees in your woodland as healthy and vigorous as possible. Competition between trees is a natural part of forest growth and development, but excessive competition as trees become more crowded and fight for growing space can make trees more susceptible to attack by insects and diseases, and damage by weather extremes like droughts. Thinning around desirable trees provides additional growing space and reduces stress on these trees. Thinning can be done by harvesting trees for firewood or other personal use products, selling trees in a timber sale, or felling or girdling trees to be left for wildlife habitat. Gradual thinning in your woodland helps maintain the vigor of the remaining trees much like thinning carrots in a garden results in larger, faster growing carrots.
Vines and invasive plants can also create problems for tree health. Some vines, like wild grape, kudzu, and Asian bittersweet, can climb over the crown of the tree, covering the leaves and reducing growth and vigor and in some cases killing the tree. Trees with large vines in their crowns may also be more susceptible to damage during wind, snow, or ice storms, due to the extra weight of the vines. Cutting vines that climb into desirable trees is a good way to protect their health. Invasive plants like Asian bush honeysuckles and tree-of-heaven can become serious competitors with native forest trees and shrubs for space, water, and nutrients required for tree growth and regeneration. Heavy infestations of invasive plant species can even change the soil environment, making it more difficult for trees to regenerate. Controling invasve plants in your woodland is an important step in encouraging long-term woodland health.
Professional foresters and arborists can help you manage the health of your woodland. You can find professional foresters through the website www.findindianaforester.org or from the Indiana Division of Forestry at www.state.in.us/dnr/forestry.
The Education Store, available through Purdue Extension, has many resources available to help you manage your woodlands. Just place the keyword "woodland" in the search field box.
Forest Improvement Handbook
Lenny Farlee, Sustaining Hardwood Extension Specialist
Hardwood Tree Improvement and Regeneration Center (HTIRC)
Forestry & Natural Resources, Purdue University