_Forest Management Studies._ Experiments in forest management are carried on to determine the best methods of cutting National Forest timber to secure natural reproduction and at the same time to improve the quality and productivity of the remaining stand. These studies are carried on by means of permanent sample plots, on which all the trees are carefully measured and recorded. First the timber is cut on the plots under different systems of management, or thinnings or improvement cuttings are made. An exact record is kept of the amount of timber removed and of the size and distribution of the remaining trees. Measurements taken at regular intervals show the precise effect of the method used on each plot. Close observations of the reproduction which takes place, brush and other forms of cover which may establish themselves, and changes in soil conditions are recorded. On similar sample plots methods of brush disposal, methods of marking timber for cutting, and thinning methods are studied. After logging there are several ways in which the resulting slash may be disposed, depending upon surrounding conditions. In some localities the brush must be burned immediately on account of the fire danger which its presence involves; in other places it must be removed because it interferes with reproduction; in still other places the brush may be scattered over the area because there is little fire danger and, in fact, the brush has been found to assist and protect reproduction. All these possibilities must be determined by experiments. Likewise in marking timber for cutting and in thinning practice various methods are possible, depending upon circumstances, the most important of which are the requirements of the species and the density of the forest. Other management studies deal with the determination by actual measurement of the volumes of trees and stands, and the growth of trees and the yields of whole forests. Reliable growth and yield data for the different species and types are necessary to properly handle timber sales as well as for forest management. They are also essential for determining damages caused by fires and trespass.