Treesearch

Western gall rust (Peridermium harknessii J. P. Moore (syn. Endocronartium harknessii (J. P. Moore) Y. Hiratsuka) is potentially a serious threat to exotic Pinus radiata D. Don plantations of New Zealand although the pathogen has not been recorded here. Mechanisms that may have prevented invasion of the pathogen include geographic isolation, biological characteristics of the fungus, stand management, and regulatory mechanisms affecting transport and establishment. Major factors may include a low probability of importation of infected seedlings, unlikely spore transport in the atmosphere...

A pulse-echo acoustic method was investigated for evaluating wood stake decomposition in the field. A total of 58 wood stakes (29 loblolly pine, Pinus taeda, and 29 aspen, Populus tremuloides) that were vertically installed (full length) in forest soils were non-destructively tested by means of a laboratory-type acoustic measurement system. The same acoustic measurements were also conducted on the wood stakes after they were removed from the soil. Compression (parallel to grain) tests were then performed on the stakes in the laboratory to obtain residual elastic and strength properties....

Until recently, Cronartium ribicola J.C. Fisch. was thought to utilize only Ribes spp. (Grossulariaceae) as telial hosts in North America. During 2004, Pedicularis racemosa Dougl. ex Benth. and Castilleja miniata Dougl. (Orobanchaceae) were proven as natural telial hosts at a subalpine site (48.634109°N, 116.570817°W, elevation 1,800 m) near Roman Nose Lake, ID, where whitebark pine (Pinus albicaulis Engelm.) and western white pine (Pinus monticola Dougl. ex D. Don) are aecial hosts, and Pedicularis, Castilleja, and Ribes spp. are common herbs/shrubs (2). During August 2006, teliospore...

Imputation is applied for two quite different purposes: to supply missing data to complete a data set for subsequent modeling analyses or to estimate subpopulation totals. Error properties of the imputed values have different effects in these two contexts. We partition errors of imputation derived from similar observation units as arising from three sources: observation error, the distribution of observation units with respect to their similarity, and pure error given a particular choice of variables known for all observation units. Two new statistics based on this partitioning measure the...

Drought conditions in much of the West, increased residential development, and elevated fuels from a century of wildfire suppression have increased wildfire risk in the United States. In light of this increased risk, an innovative wildfire risk education program in Colorado Springs was examined, which rated the wildfire risk of 35,000 homes in the city's wildland-urban interface. Evidence from home sales before and after the program's implementation suggests that the program was successful at changing homebuyer's attitudes toward wildfire risk, particularly preferences for flammable...

The object of this paper is to show the intercorrelations existing between statistics of wildfires (occurrences: N; areas burned: A), climatic parameters (precipitation: P; temperature: T) and net primary productivity: NPP. To this purpose, statistics of wildfires have been studied in several regions of the world, focusing on temperature and precipitation. The present analysis has been performed on French Mediterranean Departments (Bouches-du-Rhône, Hérault, and Var), Northern Ontario (Canada), Alicante Region (Spain), Yellowstone National Park --YNP-(USA), San Diego (California, USA)....

This study focuses on the cultural-historical environment of the 88,900-acre (35,560-ha) Valles Caldera National Preserve (VCNP) over the past four centuries of Spanish, Mexican, and U.S. governance. It includes a review and synthesis of available published and unpublished historical, ethnohistorical, and ethnographic literature about the human occupation of the area now contained within the VCNP. Documents include historical maps, texts, letters, diaries, business records, photographs, land and mineral patents, and court testimony.This study presents a cultural-historical framework of...

We describe how wilderness visitors perceive changes in wilderness use, impacts, and management. We examine how visitors have responded to change, both behaviorally and cognitively. The study was based on a sample of visitors to 19 Forest Service wildernesses in Oregon and Washington. Many respondents said the types of wilderness trips they take have changed since their earlier wilderness trips. Most perceived adverse change. Use has increased (particularly day use), resulting in crowding and a widespread sense that these places seem less like wilderness than they did in the past. Most of...

The decision of where, when, and how to apply the most effective post-fire erosion mitigation treatments requires land managers to assess the risk of damaging runoff and erosion events occurring after a fire. To aid in this assessment, the Erosion Risk Management Tool (ERMiT) was developed. This user manual describes the input parameters, input interface, model processing, and output files for version 2006.01.18. ERMiT is a web-based application that uses Water Erosion Prediction Project (WEPP) technology to estimate erosion, in probabilistic terms, on burned and recovering forest, range,...

After prescribed burns at three locations and one wildfire, rainfall simulations studies were completed to compare postfire runoff rates and sediment yields on ash-cap soil in conifer forest regions of northern Idaho and western Montana. The measured fire effects were differentiated by burn severity (unburned, low, moderate, and high). Results indicate that this dry, undisturbed ash-cap soil exhibits high runoff rates and is naturally water repellent at the surface. However, the unburned, undisturbed ash-cap soil is not highly erodible due the protective duff layer on the surface. When...