Treesearch

Over 40 outbreaks of Phytophthora ramorum have occurred in managed gardens in the United Kingdom. Three of these sites, one in the southeast of England and two in the southwest, have been closely monitored since October 2003. These sites represented differing disease scenarios at the start of monitoring, as eradication action had already taken place at the site in the southeast, whereas no action had taken place in the southwest. The progress of existing infections and the development of new infections were monitored at all sites. A number of current or previously infected areas within the...

I evaluated the Northwest Forest Plan as a model for ecosystem management to achieve social and economic goals in communities located around federal forests in the US. Pacific Northwest. My assessment is based on the results of socioeconomic monitoring conducted to evaluate progress in achieving the plan's goals during its past 10 years. The assessment criteria I used related to economic development and social justice. The Northwest Forest Plan incorporated economic development and social justice goals in its design. Socioeconomic monitoring results indicate that plan implementation to...

Managing forest disturbances can be complicated by diverse human community responses. Interview and quantitative analysis of mail surveys were used to assess risk perceptions and community actions in response to forest disturbance by spruce bark beetles. Despite high risk perception of immediate threats to personal safety and property, risk perceptions of broader threats to community and ecological wellbeing were found to be more likely to influence participation in community action. Results imply that increased dialogue between resource managers and local community residents contributes...

The widespread availability of satellite imagery and image processing software has made it relatively easy for ecologists to use satellite imagery to address questions at the landscape and regional scales. However, as often happens with complex tools that are rendered easy to use by computer software, technology may be misused or used without an understanding of some of the limitations or caveats associated with a particular application. The results can be disappointment when maps are less accurate than expected or incorrect decisions when they are treated as truth. In this paper, we...

Herbivory by wild and domestic ungulates is a chronic disturbance that can have dramatic effects on vegetation dynamics. Herbivory effects, however, are not easily predicted under different combinations of episodic disturbance such as fire, timber harvest, drought, and insect defoliation. This lack of predictability poses a substantial obstacle to effective management of ungulate herbivory. Traditional models of vegetation transition in forested ecosystems have ignored the influences of ungulate herbivory, while research on effects of herbivory have typically excluded other disturbances....

Biogeochemical models offer an important means of understanding carbon dynamics, but the computational complexity of many models means that modeling all grid cells on a large landscape is computationally burdensome. Because most biogeochemical models ignore adjacency effects between cells, however, a more efficient approach is possible. Recognizing that spatial variation in model outputs is solely a function of spatial variation in input driver variables such as climate, we developed a method to sample the model outputs in input variable space rather than geographic space, and to then use...

A total of 284 ponderosa pine growing near the southern edge of the Blue Mountains in eastern Oregon were categorized into one of three crown classes based on the degree of "tufted", or "lion's tail" appearance of their branches, a potential symptom of black-stain root disease, then pushed over and their root systems examined for visual symptoms of disease. Only 23 (8.1 %) were found to have more than a trace level of black-stain, annosum root disease, or both at about 38 cm below the root collar. Although there were many measurable differences in crown growth parameters among the three...

We investigated herbaceous richness and cover in relation to fire season and severity, and other variables, five growing seasons following prescribed fires. Data were collected from six stands consisting of three randomly applied treatments: no burn, spring burn, and fall burn. Fall burns had significantly more exotic/native annual/biennial (an/bi) species and greater cover of these species (6.5% exotic; 1.7% native) compared to spring and unburned areas. These patterns are likely related to indirect fire effects associated with fire severity and resource availability, rather than direct...

Invasive alien species have long been recognized as a leading threat to biological diversity, contributing to the decline of nearly half of the imperiled species in the United States for which threat information is available. This paper discusses some of the invasive species that threaten imperiled wildlife in the western United States, including endemic birds in San Francisco Bay, sage grouse, and grizzly bears. I present 3 examples of the difficulties inherent in balancing the need to close pathways of invasive species entry with maintaining active international and interstate trade...

The USDA Forest Service Pacific Northwest Research Station's Biodiversity Initiative seeks to determine the types of science tools needed by natural resource professionals to meet diverse and complex biodiversity goals. During the scoping phase of this Initiative, we asked a broad cross-section of people whose work involves managing for biodiversity, from state and federal agencies to private forestry companies and environmental groups, what their priority needs, challenges, and concerns were for the region's biodiversity conservation. We report here the results of our scoping phase and...