Treesearch

Mortality of nontarget small mammals was determined after application of three black-tailed prairie dog (Cynomys Zudovicianus) rodenticide treatments (prebaited zinc phosphide, prebaited strychnine, and strychnine alone) in western South Dakota. Immediate (September 1983) and long-term (September 1983 through August 1984) impacts on deer mouse (Peromyscus maniculatus) relative densities were evaluated, and the three rodenticide treatments were compared for efficacy. The three treatments had no significant (a < .l0) immediate impacts on deer mouse relative densities, although zinc phosphide...

Three rodenticide treatments, zinc phosphide with prebait, strychnine with prebait, and strychnine without prebait, were applied to black-tailed prairie dog (Cynomys ludovicianus) colonies in west central South Dakota. Results were compared immediately posttreatment and for one year after application. Zinc phosphide was the most effective for reducing prairie dog numbers immediately. When burrow activity levels of prairie dogs were initially reduced by 45% with strychnine only, they returned to untreated levels within ten months. When initial reductions were 95% with zinc phosphide,...

Rating scales provide an efficient and widely used means of recording judgments. This paper reviews scaling issues within the context of a psychometric model of the rating process, describes several methods of scaling rating data, and compares the methods in terms of the assumptions they require about the rating process and the information they provide about the underlying psychological dimension being assessed.

Artificial rainfall was applied to two sets of paired plots 30.5 m long by 1.52 m wide, each set on a different soil type. One plot in each set contained a wheel rut while the other did not. Measurements of water and sediment yield on rutted plots showed sediment production declined with cumulative runoff while unrutted plots did not show a significant sediment depletion. This difference was a result of concentrated flow versus sheet flow.

The Budworm Modeling System is a set of four computer programs: The Budworm Dynamics Model, the Prognosis-Budworm Dynamics Model, the Prognosis-Budworm Damage Model, and the Parallel Processing-Budworm Dynamics Model. Input to the first three programs and the output produced are described in this guide. A guide to the fourth program will be published separately. Publications regarding the programs' purpose, general structure, and scientific basis are listed. The modeling system is useful for studying and managing budworm-infested forests.

I studied the calling behavior of radio-tagged Mexican Spotted Owls (Strix occidentalis lucida) in northern Arizona. Owls used a variety of calls, with three call types (Four-note Location Call, Contact Call, and Bark Series) accounting for 86% of calling bouts heard. These calls were used by both sexes, but in significantly different proportions. Males (n = 4) called twice as frequently as females (n = 3), and there also appeared to be intrasexual differences in calling rates. Calling activity increased from March through May, then declined from June through November. Calling activity was...

Whitebark pine ecosystems are an important element of many of the most spectacular high-elevation landscapes in the western United States. They occupy upper subalpine and timberline zones in the prime recreation lands of the Cascades, the Sierra Nevada, and the Northern Rocky Mountains. This paper explores the nature of the recreational opportunities that the whitebark pine ecosystem provides and the demand for those opportunities. Important management problems are described, as are strategies for minimizing problems and optimizing recreational opportunities. Dispersed backcountry recreatio...

Tree-ring width chronologiesfr om ten mixed-conifers tandsi n the Colorado Front Range and New Mexico Sangre de Cristo Mountains were used to reconstruct the timing, duration, and radial growth impacts of past outbreaks of western spruce budworm (Choristoneura occidentalis Freeman). At least nine outbreaks were identified in the stands from 1700 to 1983. Severity and timing of outbreaks was highly variable. The average duration of reduced growth periods caused by budworms was 12.9 years and ranged from 5 to 26 years. The average interval between initial years of successive outbreaks was...

Describes an ecological process model of succession that simulates long-term stand dynamics in forests of the Northern Rocky Mountains. This model is used to evaluate the effects of various fire regimes, including prescribed burning and fire suppression, on the vegetation and fuel complex of a simulation stand. This report documents the model FIRESUM (a FIRE SUccession Model), examples of model output, and sensitivity analysis and validation results.

Presents highlights of Wyoming's forest resources as of 1984. Describes the extent, nature, condition, and location of forest resources and discusses levels of some nontimber use of forest land. Includes statistical tables: area by land classes, ownership, wood volumes, growth, mortality, and products removals.