Treesearch

This is the fifth and final report to assess the merits of multiband photography from aircraft and spacecraft and multispectral scanner imagery for the interpretation and analysis of nonforest (shrubby and herbaceous) native vegetation.

This paper presents the results of data analyses for 25 precipitation intensity stations on two study areas in central and north-central Utah located at elevations between 4,350 and 10,150 feet m. s. l. All data were collected during the period May 1 to October 31. Each station has 10 or more years of record; one station has 30 years of record. The following analyses were made: (1) Record consistency; (2) definition of local precipitation zones; (3) intensity-duration-frequency characteristics; (4) 24-hour depths; (5) monthly depths and number of storms; (6) storm occurrence by hour of the...

Western white pine trees resulting from crosses of parents selected for phenotypic resistance to Cronartium ribicola J. C. Fisch. ex Rabenh., the white pine blister rust, were inspected for rust infection after 11 to 15 years in two field plots. When compared to controls and to natural reproduction, the progenies of crosses involving trees that exhibited general combining ability for resistance transmission in nursery tests were much less heavily infected (20 percent on the average, as opposed to 58 and 71 percent for controls and natural reproduction, respectively).

Measurements of cores or disc samples representing slightly more than 76,000 annual rings from 336 western white pine trees were compiled to obtain a set of deviations from normal growth of healthy trees that would express the response of these trees to variation in the environment during the last 280 years. Their growth was demonstrated to be a function of temperature and available moisture for the period of climatic record from 1912 to 1958. Extrapolating the relation of growth to weather to the long tree ring record of western white pine, we find that the period 1916-40 represents the...

Seedling progenies of 36 rangewide provenances of Scots pine (Pinus sylvestris) were established in a field test in eastern Nebraska. Results in growth and other characteristics after 8 years reveal that (1) southern origins bordering the Mediterranean grow slowly to moderately fast and remain dark green in winter, (2) central European origins grow very fast and turn yellowish green in winter, (3) northern origins grow slowly and turn very yellow in winter. Southern origins are therefore recommended for Christmas trees; fast growing central European origins are recommended for windbreaks;...

Presents equations and/or computer subroutines for estimating either site index and yield capability, or both, of eight Rocky Mountain species in forest inventory compilation programs, or for other purposes such as management alternative simulations. Species included: western white pine, ponderosa pine, lodgepole pine, western larch, Engelmann spruce, inland Douglas-fir, grand fir, and quaking aspen.

Results of three studies on photosynthesis and needle water deficits are presented. Photosynthesis was higher for Engelmann spruce seedlings grown in the shade than in the open, but it was not significantly different for lodgepole pine seedlings. Spruces reached near-maximum photosynthesis at 4,000 to 5,000 ft-c, but pines did not appear light-saturated even at 12,000 ft-c. Photosynthesis and respiration of potted spruce seedlings were highest at moisture deficits less than 10 percent; with deficits above 20 percent, photosynthesis was zero and respiration minimal. At a deficit of 58...

Fourwing saltbush (Atriplex canescens (Pursh) Nutt.) is one of the most important shrubs on western ranges. Widely distributed, this plant furnishes forage for livestock and wildlife in all seasons; it is especially valuable as browse on winter ranges. Also known as chamizo in the Southwest, and as buckwheat shrub, white greasewood, soltsage, bushy atriplex, and wafer sagebrush elsewhere, fourwing soltbush derives its most common name from the characteristic four-winged fruit. Its importance is due to abundance, accessibility, size, large volume of forage, evergreen habit, high palatability...

Fire researchers working to develop more effective chemical fire retardants long have looked for a convenient way to compare effects of various fire-retardant chemicals on flammability. Flammability has been defined as the interaction of ignitibility, sustainability, and combustibility. Ignitibility is the ease with which a fuel will ignite. Under given conditions, the most ignitible fuel will ignite spontaneously with the least energy input. A measure of the ability of a fuel to continue to react exothermally following ignition quantifies the sustainability of the fuel. Combustibility of...

Rangelands in the contiguous United States include over 1 billion acres that are not suitable for cultivated crop production. These lands, however, produce native forage for domestic and wild grazing animals. They also provide recreational and intangible natural beauty benefits and circumscribe the drainages of many river systems from which domestic and commercial water supplies are derived.