Treesearch

Variation in host responses to pathogens can have cascading effects on populations and communities when some individuals or groups of individuals display disproportionate vulnerability to infection or differ in their competence to transmit infection. The fungal pathogen, Batrachochytrium dendrobatidis (Bd) has been detected in almost 700 different amphibian species and is implicated in numerous global amphibian population declines. Identifying key hosts in the amphibian-Bd system—those who are at greatest risk or who pose the greatest risk for others—is challenging due in part to many...

Our research seeks to expand the concept of urban environmental stewardship to include the everyday stewardship practices of urban nontimber forest products foragers. Ethnographic data from 58 urban foragers and 18 land stewards in the city of Seattle (USA) revealed that foragers reported using a variety of practices to enhance and minimize negative desirable species and their habitats. Many of these practices were identical to those practiced by restoration volunteers in formal programs and align with Seattle Parks Department management objectives. Foragers actively sought to learn more...

Virus–plant interactions range from parasitism to mutualism. Viruses have been shown to increase fecundity of infected plants in comparison with uninfected plants under certain environmental conditions. Increased fecundity of infected plants may benefit both the plant and the virus as seed transmission is one of the main virus transmission pathways, in addition to vector transmission. Trade-offs between vertical (seed) and horizontal (vector) transmission pathways may involve virulence, defined here as decreased fecundity in infected plants. To better understand plant–virus symbiosis...

This report describes and documents the OpCost forest operations cost model, a key component of the BioSum analysis framework. OpCost is available in two editions: as a callable module for use with BioSum, and in a stand-alone edition that can be run directly from R. OpCost model logic and assumptions for this open-source tool are explained, references to the literature used in all of the submodels included in OpCost are provided, and guidance is offered on how to change the default hourly machine rates associated with overall logging cost calculations. OpCost enhancements such as cost...

We developed a process to address terrestrial wildlife species for which management for ecosystem diversity may be inadequate for providing ecological conditions capable of sustaining viable populations. The process includes (1) identifying species of conservation concern, (2) describing source habitats, and other important ecological factors, (3) organizing species into groups, (4) selecting surrogate species for each group, (5) developing surrogate species assessment models; (6) applying surrogate species assessment models to evaluate current and historical conditions, (7) developing...

The economic linkages between national forests and surrounding areas are one of the important ways public lands contribute to the well-being of private individuals and communities. One way national forests contribute to the economies of surrounding communities is by attracting recreation visitors who, as part of their trip, spend money in communities on the peripheries of national forests. We use survey data collected from visitors to all forest and grasslands in the National Forest System to estimate the average spending per trip of national forest recreation visitors engaged in various...

The Aquatic and Riparian Effectiveness Monitoring Program focuses on assessing the degree to which federal land management under the aquatic conservation strategy (ACS) of the Northwest Forest Plan (NWFP) has been effective in maintaining and improving watershed conditions. We used stream sampling data and upslope/riparian geographic information system (GIS) and remote-sensing data to evaluate condition for sixth-field watersheds in each aquatic province within the NWFP area. Stream conditions were evaluated based on sampling data collected from 2002 to 2013 (214 watersheds) as part of an...

United States tree species and their associated ecosystems, managed forests, and urban plantings are increasingly vulnerable to non-native invasive pathogens and insects as well as effects associated with a changing climate. Some species, such as whitebark pine (Pinus albicaulis), have been proposed for listing under the Endangered Species Act. To fully assess the vulnerability of tree species and ecosystems, we need to make better use of data that shows temporal trends in mortality and forest health. With these data, forest managers and the United States public will have a greater sense...

A collaborative team of researchers from the United States and Mexico has begun an exciting new research project funded by The National Science Foundation’s Macrosystems Biology program. The project will study ecological and evolutionary processes affecting the distribution of southwestern white pine (Pinus strobiformis), an important tree species of mixed conifer forests in the southwest United States and Mexico. Southwestern white pine sustainability is threatened by changing climate, and a non-native tree disease, white pine blister rust caused by Cronartium ribicola. White pine blister...

The ecologically foundational species eastern hemlock, Tsuga canadensis, is being functionally eliminated from southern Appalachian forests by the hemlock woolly adelgid (HWA, Adelges tsugae). The management of HWA has focused on chemical and biological control, conservation of hemlock genetic resources, and host resistance breeding; however, research on the reintroduction of hemlocks to forests where it has been lost has received almost no attention. This poster presents progress made on phase one of a three phase project to develop a hemlock restoration strategy that integrates silvicultu...