Treesearch

The erosion of soils through the action of rain water and that from melting snow is almost universal in its occurrence. The gradual erosion and levelling of any country is inevitable, being a process which has gone on as long as there has been free water on the face of the earth. Nevertheless, this process is an extremely slow one where the landscape is naturally well covered by vegetation, and is greatly speeded by every mechanical disturbance of the earth's surfaces resulting from man's activities; and under certain conditions becomes needlessly destructive. The loss of fertile surface...

If white pine forests are to be made an important source of timber in the state either through planting or the proper handling of stands already established, it is essential to have the facts regarding the commercial possibilities of this tree. The facts which must be ascertained first of all are, how long does it take white pine to become merchantable, and what are the possible yields and money returns that may be expected when it has been grown? With this information as a background, one naturally wants to know how much it costs to plant, the kind of land best suited for the growth of...

The purpose in this report is to describe the natural forest types of the northern Rocky Mountains in Montana and northern Idaho, to point out their natural distribution and chief silvical characteristics, and to show in what degree they are controlled by differences in topography and climate. Such information may be useful in laying the foundation for later, more intensive silvical investigations and practices in a region rich in forest resources.

Forest planting in the northern Rocky Mountain region is largely confined to areas that have been burned over twice, the second burning occurring during recent years. Planting crews can operate on these "double burns'' with relative ease because the fires have removed shrubs and other obstructions. Unfortunately planting activity on forest lands is not keeping pace with the accumulation of areas denuded by fire, and as time passes these lands rapidly revert to shrubby growth from the uninjured roots of the original bushes and from wind-borne seeds. Released from competition, other than...

Some definite figures on the survival and seed production of seed trees left on national forest timber sales in the Douglas fir region are now available for six representative areas where approximately two trees were left per acre. The studies mere made by men in charge of timber sales on the national forests under the direction of the Experiment Station, and have now been under way from two to five years.

The knowledge of the rate at which trees grow in virgin forests, after clear cutting and under selective logging, is indispensable in any forest calculations or forest practice. The enactment of the Forest Crop Law, which brought under its operation about 175,000 acres of cut-over land during the first year, the example set by several progressive lumbermen in selective logging, and the general public interest in the future of the cut-over land focused attention acutely on what may be expected from cut-over land in the way of growth and returns in the course of the next few decades.

The quadrat method, first introduced into ecological studies by Pound and Clements in i898, has been adopted by both foresters and ecologists as one of the most accurate means of studying the occurrence, distribution, and development of vegetation (Clements, '05; Weaver, '18). This method is unquestionably more precise than the descriptive method which it superseded. Nevertheless, the results obtained are subject to certain types of experimental error in common with all methods of sampling in which it is necessary to picture conditions over large areas from representative fractions....