I would say that for the vast majority of us timbered areas comprise some portion of our property. There are very few parcels of land that are considered quality deer hunting property that do not have at least a portion that is wooded. When I discussed Cover in a previous blog, I outlined why trees have value to us as land managers. If I were to say food for deer, in terms of trees, I feel confident that most people would think of oaks and acorns they produce. However, there are other valuable, naturally occurring, mast producing trees, which can be either categorized as soft mast or hard mast. While acorns are an example of hard mast, soft mast species might be persimmons, mulberry and even wild growing apple trees in some areas of the country. However, trees can provide more than hard or soft mast. Woody browse makes up a large percentage of a deer's diet from late Fall through Early Spring and possibly even year-round depending on how common forbs, food plots and row crop agriculture is in your area. In areas of deep snow, woody browse might be the only real food source for a extended portion of the Winter. Trees to a lesser extent are a Cover source. Tall mature deciduous trees provide little in the way of Cover for deer. They are vital for turkey roosting. Coniferous trees in some situations can provide thermal cover. Even in areas with relatively mild Winters I routinely find white -tail deer beds underneath Eastern Red Cedar that are missing some of their lower branches. Deer will bed on the downwind side of coniferous trees where the wind is less and some radiant heating results from the dark foliage absorbing sunlight. Why should we manage our timbered areas?
Often times deciduous blocks of trees end up in a closed canopy state where sunlight can no longer reach the ground. In that instance a number of negative things begin to happen. 1st existing trees experience reduced productivity (in terms of mast production) as they must compete with crowding "neighbors" that are taking up sunlight, moisture and nutrients. 2nd the amount of sunlight is reduced to a point where the seeds/acorns of many desirable species cannot germinate or successfully grow as seedlings. 3rd almost all forbs and many desirable species of shrubs no longer have enough sunlight to grow. What does grow are the species of shrubs that are shade tolerant (many of which are invasive) and further out compete the desirable native shrubs that have a greater wildlife value. Finally if you are considering harvesting trees for lumber, high density stands of trees often result in very slow individual tree growth. Which means you may never see trees reach a marketable size for timber harvest. Trees such as Honey Locust and Osage Orange Hedge (which have less wildlife value compared to other species) often out compete the more desirable trees which we would like to promote. Locust and hedge trees at least in the area I live can very rapidly take over grass areas as well. So what methods can we use to manage our timbered areas?
In large parts of the Midwest where rainfall was historically somewhat limited, fire was a fairly common occurrence. Fire does a couple of things, it helps to kill off some young seedlings and even older trees to help maintain a healthy tree density level. Prescribed fire favors fire tolerant species that have thicker bark such as some oak species and Shagbark Hickory. Fire also removes the heavy leaf litter layer that can keep seeds from germinating. Implementing prescribed fire in some areas can be very challenging or even impossible due to regulations. However, in those areas where it is permissible it can be a very cost effective and productive in helping a land manager improve timber quality. What if you can't use prescribed fire or just aren't comfortable implementing it as a tool? Then timber stand thinning will need to be accomplished with either herbicide application, cutting/girdling or a combination of those 2 things. On younger trees with a diameter of less than 6" we can accomplish thinning by cutting, girdling, hack & squirt, hinge cutting and basal bark spraying. When we contemplate herbicide application we need to determine whether it is in our best interest to kill the tree outright or simply to set it back to a level where it is not competing with our desirable trees for a long period of time. By using herbicide on stumps or introducing it into the tree through a hatchet cut or a groove cut by a chainsaw we can permanently terminate that trees growth and/or regrowth. There are benefits to not killing a tree, while at the same time eliminating it from competing with more desirable species. Hinge cutting is the process of felling a tree while maintaining a strip of wood and bark connected to the stump. This drops the tree to ground level but still allows the tree to live in a weakened state for some time. Providing both some live cover and green browse that deer can reach. Generally the tree continues to live for a year or 2, but can live longer. In a sense you are converting a tree to a "bush". Hinging should only be done to smaller diameter trees 6-8" in diameter, falling larger diameter trees in this manner can be dangerous. Cutting a tree off entirely and thereby creating a stump can be beneficial as well. These stumps are not treated with herbicide and very often the trees response is to send up a large number of suckers from the remaining stump. Sometimes referred to as a Mineral Stump. The regrowth tends to be much higher in nutrition, can easily be reached by browsing deer and also provides some more cover at ground level. These stumps may die out over time, but may also have to be re-cut in the future as the shoots essentially become trees.
Cut stump regrowth Hinge Cut
Trees can be girdled with a chainsaw and the cut treated with herbicide, or the tree can be cut off completely and the stump treated with herbicide. Keep in mind that the only living tissue where water and nutrients are transported in a tree lies in the outer layer just under the barks surface. There is no benefit to wasting expensive herbicide and treating the entire cut surface to insure a kill. There is often an argument that dead trees should not be left standing. In areas of high human traffic that is probably wise. However, in most woodland situations it is safer and less costly to simply kill the tree and allow they natural decay process to bring the tree down over time. If trees are being cut for lumber production, then obviously those trees would be removed from the site at that time. Some species such as Eastern Red Cedar do not need to be treated with herbicide as long as all needles/ "leaves" are removed from the stump it will die and not resprout.
Cut Stump with Herbicide Girdling with Herbicide
Healthy timbered areas have a mix of productive mature trees (those that are actively producing mast and eventually trees for logging), good seedling germination and regrowth and plenty of forb and shrubby vegetation which serves as cover and a food source for wildlife. A healthy timbered area during the summer months has green leaves from the ground level up to the top of the canopy. We will cover TSI more as time goes along but for now this gives a overview of why healthy timbered areas are important and the techniques that can be utilized to accomplish it. In the next blog we will take a look at what affects healthy non timbered, native vegetation areas.