John Belton

Tree farmers from the foothills of the Cascade Mountains are reporting increased cambium-feeding (i.e., Bear damage). This increased damage may be due to an increased bear population now that hunting is more restrictive and there are more young Douglas-fir stands that they prefer. Bear damage occurs during spring and early summer, when the sap is running in the trees and prior to the time when berries ripen. The presence of bear damage has been highest in more productive sites, when the trees are about 10 inches dbh, where the trees have been thinned, and where Douglas-fir trees are the most abundant species. When you have bear damage you will quickly develop a dislike for the animal because they remove enough bark to cause serious damage to a tree or often kill it. A recent study done by William Stewart et.al. (Western Journal of Applied Forestry, vol. 14: pages 128-131, 1999) reported bear damage on 48% of plots selected for the presence of bear damage. A total of 239 freshly damaged trees were measured: 69% Douglas-fir, 19% western hemlock, 10% silver fir, and 2% other conifer species. They also recorded the presence of bear damage on randomly selected plots and reported the following characteristics for plots where fresh bear damage had occurred.

The Snoqualmie study area has traditionally relied on spring bear hunts and a supplemental feeding program to reduce bear depredation on trees. Despite these efforts, heavy levels of damage occurred on more than 75% of the freshly damaged sites examined. The observed frequency of high damage levels suggests that in some areas the current methods to reduce black bear damage are only marginally successful. Direct control methods have been used: snaring, either to relocate or to lethally remove the bear, and hunting. These reactive methods have aroused controversy and may result in further restrictions in the future. Indirect controls have included supplemental feeding, topical repellents applied to the bark of the trees and several silvicultural practices but the results have been variable. It is essential for forest managers to weigh the costs and benefits of each method before choosing which, if any, is appropriate for their situation. A combination of methods may be most effective (Stewart, W., G. Witmer and G. Koehler citation listed above).

The Oregon Forest Industries Council (OFIC) has just published the results from a survey on animal damage (Newsletter, vol. 11, no. 4). OFIC is informing us about the potential costs of animal control budget if a more restrictive anti-trapping initiative passes. At the present time 40% of the animal control budget is being spent to reduce bear damage in northwest Oregon. A committee of industrial foresters projected that if the anti-trapping initiative passes bear control will require much more supplementary feeding and hunting. They project that this labor intensive strategy for bear control would cost over 2 million dollars per year for western Oregon.

Master Woodland Manager, John Belton, is a Clackamas County tree farmer

From the Forest-Tree Leader, a newsletter published by the Clackamas County Farm Forestry Association