Treesearch

Recent concerns about the future for migratory birds, particularly those that migrate to the Tropics, have led to the development of a variety of new research and education initiatives addressing avian population ecology and conservation. Research that focuses on the relationships between migrant population trends, geographical patterns, and spatial and temporal scales is central to solving conservation problems for migrants. Understanding how and why avian populations are declining is difficult because population trends vary in relation to numerous factors, including species, habitat,...

The declining populations of North American landbirds that migrate to the neotropics has attracted widespread attention from resource specialists. Documented declines in populations of eastern neotropical migrants, as well as habitat fragmentation on breeding grounds and habitat loss on wintering grounds have led researchers and resource managers to increase efforts to understand and effectively manage for the long-term conservation of these bird populations. Despite this attention, little is known on the population ecology of neotropical migrants inhabiting the western United States. One...

This glossary provides standard definitions for many of the terms used in avian conservation biology. We compiled these definitions to assist communication among researchers, managers, and others involved in the Neotropical Migratory Bird Conservation Program, also known as Partners in Flight. We used existing glossaries and recent literature to prepare this glossary. The cited sources were not necessarily the first ones to use the terms. Many definitions were taken verbatim from the cited source material. Others were modified slightly to clarify the meaning. Definitions that were modified...

Natural regeneration of interior cedar-hemlock-white pine forests is usually prompt and abundant. These productive sites support up to 10 commercial timber species. Retrospective examination of cutover forest stands allowed determination of variables that are important predictors of regeneration. This report discusses variables such as habitat type, slope, aspect, elevation, residual overstory density and species composition, site preparation, and the number of years since disturbance. These variables can be used to predict stocking, density, and species composition of regeneration....

Advance conifer regeneration readily survives release from overstory competition in the Inland West, but foresters are concerned about the ability of released trees to attain normal growth rates. There are also concerns about forest health issues associated with managing advance regeneration. The best pre-release predictors of post-release growth response are pre-release vigor and crown ratio at release. The fastest growing trees before release grow the fastest following release. A general recommendation is that at least a 0.50 crown ratio at release is necessary for good response to...

Forest health is most appropriately based on the scientific paradigm of dynamic, constantly changing forest ecosystems. Many forests in the Inland West now support high levels of insect infestations, disease epidemics, fire susceptibilities, and imbalances in stand structures and habitats because of natural processes and past management practices. Impending, potentially catastrophic fires can be avoided or modified through proactive forest health management-protecting, creating, and maintaining stand structures, processes, and species populations at viable levels across substantial...

Stream reaches that have been rested from livestock grazing appear to have stable banks and more bank undercuts than grazed stream sections. Ungrazed reference streams that are similar in parent geology, precipitation, channel type, habitat types, drainage area, and stream width had greater bank stability values and lower width-todepth ratios than those of grazed and rested management sections of Silver King Creek. Power curve analysis was used to suggest the sample sizes required to monitor progress toward the desired condition.

Variance approximations are derived for the weighted and unweighted kappa statistics, the conditional kappa statistic, and conditional probabilities. These statistics are useful to assess classification accuracy, such as accuracy of remotely sensed classifications in thematic maps when compared to a sample of reference classifications made in the field. Published variance approximations assume multinomial sampling errors, which implies simple random sampling where each sample unit is classified into one and only one mutually exclusive category with each of two classification methods. The...

The bark beetle antiaggregative pheromones, verbenone and ipsdienol, were tested in protecting heat-injured lodgepole pine (Pinus contorta Dougl. ex Loud.) from mountain pine beetle (Dendroctonus ponderosae Hopkins) infestation in the Sawtooth National Recreation Area in central Idaho. Peat moss was placed around 70 percent of the basal circumference of lodgepole pines. When the peat moss was ignited, it simulated the smoldering of natural duff, generating temperatures that killed the cambium. The four treatments tested were uninjured tree, heat-injured tree, heat-injured tree treated with...

Great gray owls (Strix nebulosa) inhabit forests, but not all forests possess identical characteristics. To understand the owl, we must understand the dynamics of the vegetation communities that support them. Those dynamics operate differently in the Northern Rocky Mountains and the Cascade-Sierra Nevada complex, both of which are inhabited by great gray owls.