Treesearch

Introduction: Tree defense characteristics play a crucial role in modulating conifer bark beetle interactions, and there is a growing body of literature investigating factors mediating tree growth and resin-based defenses in conifers. A subset of studies have looked at relationships between tree growth, resin duct morphology and climate; however, these studies are almost exclusively from lower-elevation, moisture-limited systems. The relationship between resin ducts and climate in higher-elevation, energy-limited ecosystems is currently poorly understood. Methods: In this study, we: (1)...

Specific heat capacity of red oak and Douglas fir was measured from 0°C to 438°C using differential scanning calorimetry to provide input parameters for fire modeling. Techniques that allow for measurement of the standard heat capacity, excluding the effects of heat of reaction, were explored. Results show the specific heat capacity of wood becomes nearly constant with increasing temperature once pyrolysis starts. Furthermore, for both species of woods, the heat capacity values level out at a higher temperature than leaves, with correspondingly higher final specific heat capacity values.

Peatlands have sequestered atmospheric carbon dioxide (CO2) for millennia and can also act as significant sources of atmospheric methane (CH4). Hydrological processes that control water table dynamics, and climatic conditions such as air temperature, play important roles in mediating peatland-atmosphere exchange of these greenhouse gases. These controls are likely to be impacted by climate change, particularly for those peatlands found in cold environments, including mountain regions. In this study, we developed empirical models to simulate hydrological dynamics and ecosystem-atmosphere C...

Birds do it. Bats, butterflies, flies, wasps, and, perhaps most importantly, bees, do it, too. By gathering and transporting DNA-containing pollen from plant to plant, these flying animals are critical for the successful reproduction of flowering plants. Bees and other pollinators are crucial for maintaining biodiversity and, by supporting healthy plant communities, a long list of ecosystem functions (food and habitat for animals, soil stability, and water quality, to name a few).

Falling trees and tree fragments are one of the top five leading causes of fatalities for wildland fire responders. Wildfires - along with insect infestations, drought, disease, and other disturbances - have increased dead and dying trees in forests across the western United States.

White pines in North America face threats including the nonnative blister rust pathogen, mountain pine beetle, wildfires, and other consequences of rapid climate change. These grand trees need protection to restore and maintain a diverse forest ecosystem. Radial thinning - clearing a prescribed radius around each tree - is one treatment that researchers and managers are testing to possibly increase vigor and decrease mortality, while still maintaining high forest cover. This type of treatment is sometimes used when heavier, stand-level thinning is not a viable option due to social or...

Building containment lines and removing fuels can bring wildland firefighters close to advancing flames. In these high-risk situations, firefighters depend on safety zones - large, open areas with little flammable material where they can retreat if conditions turn dangerous.

While sampling freshwater fish across Montana and northern Idaho about 15 years ago, Michael Young, a research fish biologist at the USDA Forest Service Rocky Mountain Research Station, became interested in the taxonomy for sculpins. “Biologists across the West, including us, were resorting to labeling our field-collected specimens as ‘Cottus sp.,’ which is shorthand for ‘we don’t know what we’re looking at,’” Young recalled. “We got fed up not knowing the identity of these fish and decided to do something about it.”

As wood is exposed to high temperatures, pyrolysis begins, permanently altering the material properties as volatiles and char are formed. The rate at which char is formed is used to predict failure times for timber members and has been shown to be inversely related to the density of the wood. Because the density is a function of local exposure temperatures, it is inherently difficult to measure and typically is simplified to a single bulk value for either unmodified wood or the density of wood and char. Here, we report the use of two fast, simple density measurement techniques to characteri...

One fundamental question is driving Mexican spotted owl management research: What is happening to owl habitat? Scientists with the USDA Forest Service’s Rocky Mountain Research Station (RMRS) along with partners have developed a methodology for tracking long-term trends in Mexican spotted owl habitat in the southwestern United States. The project analyzed nearly 3,000 known owl nest and roost sites, data from the Forest Service’s Forest Inventory and Analysis program, Landsat imagery going back to 1986, and regional climate and local topographic information to create predictive owl habitat...