Treesearch

Foresters generally accept without alarm the normally small but continuing losses caused by the indigenous agents of mortality in forest stands. When a stand suffers a sudden increase in the rate of mortality, however, attention is focused upon the subject and a host of questions and speculative answers arise. How much growth is nullified by mortality during a rotation? What are the causes of mortality and how important is each one? Is there any relationship between the cause of mortality and the age, density, composition, or other qualities of the stand? How much mortality might be...

Lightning is the major cause of fires in Rocky Mountain forests. The lightning fire problem is the prime target of a broad research program now known as Project Skyfire. KEYWORDS: lightning, fire research

The 65 million acres of winter range in the Intermountain region supports only a sparse stand of vegetation, yet it furnishes forage for approximately 4 to 5 million sheep each winter for a period of 4 to 6 months, from November to April. Since the early days of the sheep industry in the West, the drier portions of the region have been used for winter grazing. These semiarid ranges are well suited for such use because the forage is composed of grasses and low shrubs that grow during the spring and early summer, then dry and cure on the stem before grazing begins. Light snowfalls, usually...

Stockmen and managers of western range lands, both public and private, are vitally interested in stocking their ranges on a basis that will assure sustained forage and livestock production at a high level. It is recognized that if ranges are stocked too heavily, the vegetation deteriorates, producing less forage and less livestock. On the other hand, too light grazing fails to make use of forage that is available, and livestock production is less than it should be. This problem of proper stocking is especially important to stockmen and ranchers of the Front Range of Colorado. Many of them...

Summer cloudburst storms occur frequently on the eastern flank of the Colorado Range below 9,000 feet elevation. The intensity of these storms is high, often exceeding three inches per hour for 10-minute intervals. Floods from the cloudburst storms cause much damage to lands and improvements in the adjacent plains. A considerable portion of this damage is due to sediment deposited in stream channels and reservoirs, across mountain roads, in homes and towns, in irrigation canals and ditches. Sediment damage amounts to over $600,000 annually in the South Platte River system above Greeley,...

The forest industry of the Inland Empire depends on the production of western white pine (Pinus monticola Dougl.) as a major species. Continued production of this tree is impossible unless white pine blister rust (Cronartium ribicola Fischer) is controlled. Existing merchantable timber can and probably will be harvested before serious losses occur, but the young growth that will determine the future of the industry is the great value at stake. The stakes are large. According to Matthews and Hutchison, "A lumber industry with white pine has greater prospects for security, stability, and...

Under cooperative encouragement from several Federal agencies, the Engineering Experiment Station of the University of Idaho has been studying the principles, development, and use of high-altitude precipitation gages. A low-speed wind tunnel has been used to study the effect of wind on the catching characteristics of model storage precipitation gages. A snow storm was simulated with sawdust, and various gage designs without windshields and with different type windshields were studied. Special techniques with photography were used to evaluate the value and improvement in performance of...

In 1928 Congress passed the McSweeney-McNary Forest Research Act authorizing a comprehensive survey of the timber supplies in the United States. Responsibility for this survey was assigned to the Forest Service of the Department of Agriculture. The work in Montana has been under the direction of the Northern Rockv Mountain Forest and Range Experiment Station. This is a report on the findings of the Montana survey.

The central section of the Rocky Mountains within Colorado and Wyoming is an important water-yielding area. Stream flow which originates in the mountains supplies water for irrigation, power generation, and domestic use. The actual source of most of this water is located above 8,000 feet in elevation. Here snows are heavy and water yields run as high as 24 inches per year.

This is a second report on the chromosome numbers of native and introduced grasses. The first report (Brown, 1950) concerned the chromosome numbers of eighty species in thirty-eight genera of nine tribes of the Gramineae. The present is the result of a cytological study of forty-four species (all but two additional to the first report) in twenty-four genera of five tribes. As in the previous paper, identification and nomenclature of all United States grasses are according to Hitchcock (1935). Herbarium specimens have been made of parts of the plants studied and are filed in the University...