Treesearch

Image density differences in color infrared aerial photos can be used to discriminate individual shrub and tree species of a pinyon pine-juniper plant community. In addition, image density was used successfully to identify six general plant communities: ponderosa pine, spruce-fir, aspen, big sagebrush, native grasslands, and seeded grasslands. However, different sites and cultural treatments within native grasslands and ponderosa pine forest could not be so easily discriminated, even though visual differences were apparent in the photos.

The relation between vigor of dwarf mistletoe (Arceuthobium vaginatum subsp. cryptopodum) bole infections and diameter of ponderosa pine was evaluated in several areas in Colorado. Infections which occur where the bole is over 5 inches in diameter seem to pose little threat to surrounding trees. In this study all such trees were over 7 inches d.b.h.

My work is primarily concentrated at the Manatwa Forest, in the ponderosa pine zone about 28 miles northwest of Rock Springs. The area is primarily cattle grazing land, with most of the grazing occurring in the natural openings of the pine zone. Additional livestock grazing occurs in the small openings among the trees, and very little underneath the dense canopy. In terms of herbage, protected grasslands in this area get up to nearly 2,000 pounds per acre, while if they are grazed at all we get somewhere between 12-1300 pounds. In the open timber type herbage levels drop down to about 500...

This Paper, intended as a guide for professional foresters, describes major silvicultural conditions likely to be encountered in the Black Hills, reasonable treatment options, and probable results and implications of these treatments. It also describes silvical characteristics and behavior of Black Hills ponderosa pine, and a variety of proven silvicultural tools.

Growth of bearberry varied widely between plants and between sites. Most annual growth (66 percent] occurred during June when moisture and temperature conditions were apparently optimum. Annual growth can readily be recognized by the presence of nodes and by color changes.

Survival and height growth data were collected after five field growing seasons from ponderosa pine progeny representing 75 provenances of natural stands in the Great Plains and Northern Rockies. Results showed that trees from no other provenance survived significantly better or grew significantly taller than trees from the Black Hills. Trees from southern Colorado, New Mexico, and western Montana showed significantly poorer survival and height growth. High mortality evidently resulted from a combination of intense grass competition and root rot.

Describes the status of our knowledge of ponderosa pine silviculture in the southwestern States of Arizona, Colorado, New Mexico, and Utah. Economic value, impact on other uses, and the timber resource are discussed first, followed by ecological background, site quality, growth and yield, and silviculture and management. Relevant literature is discussed along with observations, experience, and results of unpublished research. Treatise is intended to serve as a reference tool for guidance in making management decisions and prescribing silvicultural treatments. Research needs are also...

The 1974 Servicewide Silviculture Work Conference was held in Sacramento, California, on October 21-25, 1974. The objectives were to discuss tree improvement and fertilizer programs.

Fuel and fire potential in clearcut lodgepole pine were compared after stands were logged to near complete and conventional utilization standards. After logging, material greater than 3 inches in diameter had been reduced threefold on the near complete units and had been increased threefold on the conventional units. Material smaller than 3 inches in diameter was slightly less plentiful on the near complete units than on the conventional units after logging; however, of this material, the conventional units retained 2.6 times more needles. Compactness of logging residue was twice as great...

Trees successfully and unsuccessfully attacked by mountain pine beetles have several symptoms in common, so that proper diagnosis is not always easy. Guidelines presented here enable the observer to correctly distinguish nearly all attacked trees.