Treesearch

Following Euro-American settlement in the late 1800s, fire suppression and livestock grazing in ponderosa pine-bunchgrass ecosystems of the southwestern US resulted in the replacement of grass openings with dense stands of ponderosa pine. This, in turn, has led to apparent decreases in decomposition, net N mineralization, and soil respiration (i.e., net soil CO2 efflux) rates, losses of floral and faunal diversity, and greater risk of the occurrence of stand-replacing wildfire. Alterations in ecosystem structure and function have prompted the implementation of restoration treatments...

Annually emerging cicadas are a numerically and ecologically dominant species in Southwestern riparian forests. Humans have altered disturbance regimes that structure these forests such that floods are less common and wildfires occur more frequently than was historically the case. Impacts of these changes on primary consumers such as riparian cicadas are unknown. Because cicadas are consumed by a variety of animal species, disturbances that alter timing of their emergence or abundance could have consequences for species at higher trophic levels. We trapped emerging cicadas (Tibicen...

During 2005, the USDA Forest Service celebrated its Centennial, recognizing 100 years of successfully caring for the land and serving people. The Rocky Mountain Research Station has been, and continues to be, an integral part of the Forest Service mission, dating back to the Agency's beginning, with the establishment of the Santa Rita Experimental Range near Tucson, Arizona in 1903. Since then, the Station has grown, adapted, modernized, diversified, and transitioned into a world-class leader in natural resources research and development. It is the largest, most diverse station in the...

The importance of plant volatiles in mediating interactions between plant species is much debated. Here, we demonstrate that the parasitic plant Cuscuta pentagona (dodder) uses volatile cues for host location. Cuscuta pentagona seedlings exhibit directed growth toward nearby tomato plants (Lycopersicon esculentum) and toward extracted tomato-plant volatiles presented in the absence of other cues. Impatiens (Impatiens wallerana) and wheat plants (Triticum aestivum) also elicit directed growth. Moreover, seedlings can distinguish tomato and wheat volatiles and preferentially grow toward the...

Wildfire is a potential threat to many species with narrow environmental tolerances like the Rocky Mountain tailed frog (Ascaphus montanus Mittleman and Myers, 1949), which inhabits a region where the frequency and intensity of wildfires are expected to increase. We compared pre- and post-fire counts of tadpoles in eight streams in northwestern Montana to determine the effects of wildfire on A. montanus. All streams were initially sampled in 2001, 2 years before four of them burned in a large wildfire, and were resampled during the 2 years following the fire. Counts of tadpoles were...

Inappropriate development or land use on private inholdings in a matrix of predominantly public land have the potential to profoundly impact backcountry landscapes. Beyond damage to natural systems and cultural resources, ramifications include impacts on neighboring communities dependent upon tourism and backcountry recreation for their economic vitality. Limited financial resources make geotechnologies an ideal tool for prioritizing inholdings for land conservation acquisition or other means of protection. The World Wide Web holds tremendous promise for distributing geographic information...

The purpose of this study was to determine the extent to which individuals process natural resource-related information in a biased manner. Data were gathered using surveys administered to students enrolled in undergraduate classes at Colorado State University. Students' attitudes toward Arctic drilling were evaluated both before and after they were exposed to exaggerated information about both sides of the issue. Consistent with initial expectations, respondents' attitudes did not change as a result of exposure to new information. Respondents defended their initial attitudes in rating the...

The study included field data collected from outbreak areas of Norway spruce beetle Ips typographus L., which were used to identify stand conditions associated with outbreak populations. In 2001-2002 data from 100 infested and 100 uninfested plots were collected from eight Forest Districts of State Forests and three National Parks in northeastern Poland. Among 17 analyzed variables only the number of trees for all species resulted in a significant difference between infested and uninfested stands. To develop probability of infestation models, a statistical technique called Classification...

Estimates of the location and extent of the red-attack stage of mountain pine beetle (Dendroctonus ponderosae Hopkins) infestations are critical for forest management. The degree of spatial and temporal precision required for these estimates varies according to the management objectives and the nature of the infestation. This paper outlines the range of information requirements associated with mountain pine beetle infestations, from the perspectives of forest inventory, planning, and modeling. Current methods used to detect and map red-attack damage form a hierarchy of increasingly...

Unmanaged recreation presents a challenge to both researchers and managers of outdoor recreation in the United States because it is shrouded in uncertainty resulting from disagreement over the definition of the problem, the strategies for resolving the problem, and the outcomes of management. Incomplete knowledge about recreation visitors’ values and relationships with one another, other stakeholders, and the land further complicate the problem. Uncertainty and social complexity make the unmanaged recreation issue a wicked problem. We describe the wickedness inherent in unmanaged recreation...