WEED-CONTROL AND VOLES IN FOREST CULTIVATIONS

The vegetation in forest cultivations is an important factor for the occurrence of harmful voles which can gnaw the roots and the bark of the young trees. The influence of weed control upon the density of rodents was observed during ten years in several tree plantations in Bavaria. In 27 mowed cultivations the number of harmful voles was reduced by about one third in comparision to 25 untreated cultivations. However, there is a risk to injure the young trees by mowing. The voles are attracted by the effluent assimilates and can learn by this way to gnaw the bark from the wounded and subsequently also from the intact trees.