Treesearch

Describes a method for appraising fuels and fire behavior potential in aspen forests to guide the use of prescribed fire and the preparation of fire prescriptions. Includes an illustrated classification of aspen fuels; appraisals of fireline intensity, rate of spread, adjective ratings for fire behavior and probability of burn success; and evaluations of seasonal change in live fuel moisture contents.

Pronghorn antelope are important components of grassland and steppe ecosystems in Wyoming. Monitoring data on the size and population dynamics of these herds are expensive and gathered only a few times each year. Reliable data include estimates of animals harvested and proportion of bucks, does, and fawns. A deterministic simulation model has been used to improve estimates of population size. Expert judgement is employed for initial estimates of natural mortality; adjustments are made until the simulation satisfactorily agrees with field data.

CHEAPO II provides supplemental economic analysis capability for users of version 5.1 of the Stand Prognosis Model, including recent regeneration and insect outbreak extensions. Although patterned after the old CHEAPO model, CHEAPO II has more features and analytic capabilities, especially for analysis of existing and uneven-aged stands.

Survival was highest and height growth greatest in ponderosa pine provenances from northcentral Nebraska, southwest South Dakota, and the High Plains region. Genotype x environment interaction was minimal in central and northern Great Plains plantations. Age/age correlations indicate provenances expressing superior height growth can be identified after 5 or 10 years.Dataset for this publication

The pursuit of recreational activities inevitably has an effect on the resource--vegetation, soil, wildlife, and water. Whether these impacts are considered to be positive or negative depends on the management objectives of the area affected. The severity of the positive or negative response, which dictates the acuteness of the need for mitigation measures, is also influenced by management objectives. Generally, the problems associated with a given level of impact increase as we move from the more urban and developed end of the recreational opportunity spectrum toward the primitive and...

Twenty-two campsites in the Eagle Cap Wilderness were examined in 1979 and then reexamined in 1984 to compare the extent of ecological impacts. Of the 22 campsites, six had received low use, six moderate use, and 10 high use, Of the high-use sites, six had been closed to use in the late 1970’s by a regulation prohibiting camping within 200 ft (61 m) of lakeshores. This stratification made it possible to evaluate whether or not change over time was related to amount of use. It was also possible to evaluate the effectiveness of campsite closures in promoting recovery.

Vegetation and soil samples were collected from a uranium mill tailings site and control sites in South Dakota. Uranium concentrations in soils from the mill tailings averaged 13.3 [micro]g g-1 compared to 5.1 [micro]g g-1 in soils from control sites. 226Ra concentrations in soils averaged 111.0 pCi g-1 and 1.8 pCi g-1 from the mill tailings and control sites, respectively. Uranium concentrations in plants from the mill tailings averaged 3.6 x 10-1 [micro]g g-1, but only 3.4 [micro]g g-1 from control sites. 226Ra in plants from the mill tailings averaged 2.9 pCi g-1 compared to 3.7 x 10-2...

Hosts, distribution, symptoms and signs, disease cycle, and control measures are described for 46 hardwood and 15 conifer diseases. Diseases in which abiotic agents are contributory factors also are described. Color and black-and-white illustrations that stress diagnosis and control are provided. A glossary of technical terms and indexes to hosts, pathogens, and insect vectors also are included.

Differences between Prognosis Model versions 4.0 and 5.0 are described. Additions to version 5.0 include an event monitor that schedules activities contingent on stand characteristics, a regeneration establishment model that predicts the structure of the regeneration stand following treatment, and a COVER model that predicts shrub development and total canopy cover. Program performance has been enhanced by modifications to several of the submodels that predict tree increments.

Measurement of gamma radiation using thermoluminescent dosimeters on three uranium mill tailings areas and a control area showed exposure rates below ground depended on the amount and type of soil covering. Covering tailings with 30 cm of shale and 60 cm of topsoil reduced gamma radiation exposure belowground to rates similar to the control area. Soil covering of 30 cm was adequate to reduce gamma radiation exposure rates aboveground to background levels. Gamma exposure rates to small mammals were correlated to measurements belowground near the surface. Gamma radiation exposure to small...