Control of vegetation in preparation for reforestation temporarily removes a substantial portion of the ground cover. The results of this are, in effect, the conservation of soil moisture, release of soil nutrients, and removal of food and cover for certain small mammals. These site resources are not bound by living roots. Devegetation can cause the loss of soil nutrients if soil remains bare during periods of warm rain. It will also cause a marked decrease in most wildlife activity during the period of devegetation.
Herbicides are generally quite immobile in soil.
A compound that has an effective life of several months will usually not travel in solution more than a foot or two from the site of application. Herbicides, therefore, do not pose a serious threat to water supplies and have negligible potential effects on fish exposed through herbicide movement in soil. It has been demonstrated that if herbicides are not placed directly in forest streams, they will not occur in water in biologically active amounts. Insecticides Insecticides have no direct effect on vegetation. Therefore, they do not have major direct effects on the entire forest as do chemicals used to control woody vegetation.