Treesearch

Accurate, low cost measurements of forage utilization by livestock are essential in range management and the evaluation of grazing systems. However, because of difficulty in making these measurements, visual estimates often are substituted for measured values. To help land managers better determine use, range utilization calculating charts (Crafts 1938, NRCAB 1962) have been revised into a utilization gauge. Height-weight distributions of two additional southwestern grasses have been measured and incorporated into this gauge.Grass gauges are currently available through Colorado State...

Presents weather data summaries (1934-82) for most of the weather stations within the Coram Experimental Forest (a Biosphere Reserve) in northwestern Montana and for three stations adjacent to the Forest. These data aid in the interpretation of silvicultural and other biological research, particularly the relationships of climatological variations to forest growth and productivity.

The extent of Marssonina leaf blight (Marssonina populi) on quaking aspen (Populus tremuloides) was observed in northern Utah and adjacent States in 1981 aand 1982. Area of the epidemic and symptoms of the disease are described. On 1,000 acres (405 hal) in northern Utah, infection levels were 6 percent slight, 12 percent light, 32 percent moderate, 16 percent moderately heavy, and 34 percent heavy.

Daily activity budgets of male and female Abert's Towhees (Pipilo aberti) were measured in 1980 during the reproductive cycle and then converted into energy budgets to determine the relative demands of different nesting phases. Mean daily energy expenditures (DEEtot) in males reached a seasonal maximum of 126.7 kJ, or 2.16 times basal metabolic rate (BMR), in the prenesting phase. Thermoregulatory demands accounted for higher energy expenses in this phase. The cost for females was also high in the pre nesting phase but was exceeded by DEEtot in the egg-laying phase. Average DEEtot was at a...

Abert's Towhee (Pipilo aberti) is restricted to desert riparian zones of Arizona and bordering states (Phillips et al., The Birds of Arizona, Univ. Arizona Press, Tucson, Arizona, 1964). Its breeding behavior, communication, and physiological responses have been detailed by Marshall (Condor 62:49-64, 1960; pp. 620-622 in Proc. XIII Int. Omithol. Congr., Ithaca, New York, 1962; Condor 66:345-356, 1964), and Dawson (Univ. Calif. Publ. 2001. 59:81-124, 1954), but no information is available on annual productivity. Abert's Towhee is multibrooded, and therefore, the number of broods per season...

Among factors selecting for rapid growth rates in avian young are those that cause mortality of whole broods (e.g., predation, weather) (Ricklefs, Ecology 50:1031-1039, 1969). Abert's Towhee (Pipilo aberti) endures a high rate of nesting mortality caused by predation and brood parasitism (Finch, Condor 83:389, 1981; Condor 85:355-359, 1983). Predation is the principle factor causing loss of whole broods. Nesting mortality may have an important role in the development of life history traits (e.g., nestling growth, clutch-size, number of broods/season) in Abert's Towhee, yet little is known...

Advance regeneration is an important component in many stands scheduled for harvesting. Properly managed, such regeneration can contribute to a healthy, new stand, but too often trees do not quickly respond to the new environment or take too long to adjust. Definitions of acceptable advance regeneration are needed for pre- and postharvest inventories. The author discusses how to develop criteria for acceptable advance regeneration and guidelines for conducting inventories.

This guide for range managers and users is a distillation of the most important research findings over the past 50 years. The research provides a strong scientific basis for planning and decisionmaking in the management of the saltdesert shrub rangelands of the Great Basin and lntermountain areas, which cover some 40 million acres. Much of the research took place in the USDA Forest Service's Desert Experimental Range in southwestern Utah.

Techniques for locating, capturing, and monitoring activities and movements of Flammulated Owls were developed during four years of study. Adults responded to imitated territorial song throughout the nesting season. Nests were found by noting vocalizations and behaviors associated with courtship-feeding and food transfers between the sexes. After fledging, broods were difficult to follow, unless the young or adults were radio-tagged. Adults and young were captured with noose poles, hoop nets, and mist nets. Backpack harnesses and tail-mounted transmitters were used on adults and backpacks...

Volume and biomass equations were developed for curlleaf cercocarpus (Cercocarpus ledifolius Nutt.) in the Egan and Schell Mountains near Ely, NV. The equations predict cubic foot volume of wood and bark for variable minimum branch diameters. Wood density factors are given to convert volume predictions to pounds of fiber biomass. The reliability of the equations was assessed using the jackknife technique to construct confidence intervals.