Treesearch

Three kinds of weather control the fluctuations of forest-fire danger-wet weather, dry weather, and windy weather. Two other conditions also contribute to the fluctuation of fire danger. These are the occurrence of lightning and the activities of man. But neither of these fire-starting agencies is fully effective unless the weather has dried out the forest materials so they are dry enough to burn.

In any fire-ridden forest region, such as north Idaho, there is great need for a tangible basis by which to judge the length and the intensity of the fire season in different forest types and at different elevations. The major and natural forest types, such as the western yellow pine forests, the western white-pine forests, and the subalpine forests occur in altitudinal zonations one above the other and are the result of differences in air temperature and precipitation which affect not only life, growth, and distribution, but the fire hazard as well. It follows, therefore, that in addition...

In experiments with the western yellow pine (Pinus ponderosa) at the Savenac Nursery at Haugan, Mont., many helpful things have been learned, although it may now be seen that the first years of experimentation were not as effective as they might have been. The problem was attacked in much the same way as that of the western white pine (Pinus monticola), because at that time there was no means of knowing that the western yellow pine has no such decided preference for one season of sowing over another as is the case with the western white pine. For at least two seasons sowings were made in...

Planting denuded forest lands with nursery stock is the dependable and established way to get new forest crops started. The fact, however, that it is in many places an operation involving heavy expenditures has led the American forester to try out other methods to a considerable extent. His characteristic discontent with established practice as such, and his constant and persistent efforts to discover better ways, have led him to give not a little attention to field sowing as a possible short-cut in the artificial regeneration of forests. He considers that it is certainly successful under...

If all sizes of material produced by a forest are salable, very little logging debris of slash remains to hinder the reproduction or to increase the fire hazard. In the white-pine type of northern Idaho, however, only the larger and most valuable forest products can at present be taken out at a profit. The virgin forests of this region yield from 15,000 to 40,000, and often 50,000, board feet per acre. They usually contain many fallen dead trees. Much material, in the form of branches, tops, and swamped undergrowth, is left after a logging operation. This debris may cover from 40 to 90 per...

Experiments to determine the best time to sow seed of western white pine (Pinus monticola) have been under way in the northern Rocky Mountain region since 1912, partly in northern Idaho at the Priest River Forest Experiment Station, but mainly at the Savenac nursery on the Lolo National Forest in western Montana. Climate and soil combine to make the problem essentially local, but although the findings may not apply directly elsewhere the observations may be found suggestive

Unfortunately the beautiful hardwood trees which are native to the Eastern States do not grow naturally in the West. We have here only aspen, cottonwood, small birch, hawthorns, cherry, and alder. On the Pacific coast are oak and maple, but limited largely to lower moist sites such as streams bed and canyons. The general absence of broad leaf trees in the West is most likely due to the difference in precipitation and temperature between the East and West. To be sure, there are other factors which limit the distribution of trees, such as soil acidity, alkalinity, soil and atmospheric...

With a view to securing reliable data on the effects of cutting on growth and reproduction as a basis for revision of marking rules, the Forest Service about 10 years ago initiated a study of cut-over areas in the national forests of California. Some results of the study are presented to show what has actually been accomplished as a basis for sound future development in methods of cutting.