Treesearch

Depending on tree and site characteristics crown biomass accounts for a significant portion of the total aboveground biomass in the tree. Crown biomass estimation is useful for different purposes including evaluating the economic feasibility of crown utilization for energy production or forest products, fuel load assessments and fire management strategies, and wildfire modeling. However, crown biomass is difficult to predict because of the variability within and among species and sites. Thus the allometric equations used for predicting crown biomass should be based on data collected with...

Biomonitoring can provide cost-effective and practical information about the distribution of nitrogen(N) deposition, particularly in regions with complex topography and sparse instrumented monitoring sites. Because of their unique biology, lichens are very sensitive bioindicators of air quality. Lichens lack acuticle to control absorption or leaching of nutrients and they dynamically concentrate nutrients roughly in proportion to the abundance in the atmosphere. As N deposition increases, nitrogen-loving eutrophiclichens become dominant over oligotrophic lichens that thrive in nutrient-poor...

The 33 species of Agrilus (Coleoptera: Buprestidae) hypothesized to be most closely related or most similar to Agrilus planipennis Fairmaire (the emerald ash borer), are described and illustrated. Morphology (adults and immatures), biology, distribution, detailed taxonomic history and systematics are presented for each species, along with a full literature review and bibliography. Large, high resolution photos displaying all diagnostic characters are presented as well as an illustrated dichotomous identification key to adult species of Agrilus treated in this work. A general review of...

Wildfires destroy thousands of buildings every year in the wildland urban interface. However, fire typically only destroys a fraction of the buildings within a given fire perimeter, suggesting more could be done to mitigate risk if we understood how to configure residential landscapes so that both people and buildings could survive fire.

Population size and density estimates have traditionally been acceptable ways to track species’ response to changing environments; however, species' population centroid elevation has recently been an equally important metric. Packera franciscana (Greene) W.A. Weber and A. Love (Asteraceae; San Francisco Peaks ragwort) is a single mountain endemic plant found only in upper treeline and alpine talus habitats of the San Francisco Peaks in northern Arizona and is listed by the U.S. Fish and Wildlife Service as a Threatened species under the Endangered Species Act. We used 2 recreational...

Wildfires have been increasing in size and severity over recent decades. Forest managers use fuel treatments, including tree thinning and prescribed burning, to reduce the risk of high-severity fire. The impact of fuel treatments on carbon dynamics is not fully understood; previous research indicates that because carbon is removed during fuel treatments, the net effect may not be a reduction of carbon lost in the case of wildfire. The Rodeo-Chediski Fire, which burned in Arizona in 2002, was one of the largest and most severe wildfires recorded in the southwestern United States. Our...

A synthesis for fire managers summarizes and interprets a body of information, presents its meaning in an objective, unbiased way, and describes its implications for decisionmakers. Following are suggestions for ways to strengthen syntheses on fire and on other natural resource issues: Include managers, scientists, and science delivery specialists in planning, developing, and delivering syntheses. If a synthesis has unique regional components, include someone from each region in the planning team and consider these needs in writing and packaging. Use managers as authors, co-authors, or...

Hydrogeomorphic processes operating at watershed, process zone and site scales influence the distribution of riparian vegetation. However, most studies examining the relationships between hydrogeomorphic processes and riparian vegetation are conducted at site scales. We quantified the relative importance of watershed, process zone and site geomorphic characteristics for predicting riparian plant community types and plant species abundances in four small mountain watersheds in central Nevada, USA.

Main results and important changes in China’s NFI are documented, both to support continued trend analysis and to provide data users with historical perspective. New technologies and data needs ensure that the Chinese NFI, like the national inventories in other countries, will continue to evolve. Within the context of historical change and current conditions, likely directions for this evolution are suggested.

Particulate organic matter (POM) processing is an important driver of aquatic ecosystem productivity that is sensitive to nutrient enrichment and drives ecosystem carbon (C) loss. Although studies of single concentrations of nitrogen (N) or phosphorus (P) have shown effects at relatively low concentrations, responses of litter breakdown rates along gradients of low-to-moderate N and P concentrations are needed to establish likely interdependent effects of dual N and P enrichment on baseline activity in stream ecosystems. We established 25 combinations of dissolved inorganic N (DIN; 55-545...