Treesearch

In April 1856, a surveyor named Granville McPherson, toiling in the rugged hills north of present-day Harrison, Arkansas, was growing increasingly frustrated. The source of his aggravation was a deeply flawed original land survey filed by one of his predecessors, Charles H. Pelham. Years earlier, Pelham had sworn under oath that he had faithfully executed an original survey of this area to fulfill a contract with the U.S. government's General Land Office (GLO). An accumulation of evidence suggested otherwise, however. Many in Arkansas were well aware of Pelham's surveying inadequacies....

Desmognathus comprises 21 currently recognized species of salamanders in eastern North America. Assemblages of 3–6 species occur in the Appalachian Mountains, wherein the larger species are more aquatic and the smaller more terrestrial. Adaptive divergence along the habitat gradient from stream to forest involves variation in such life-history traits as age and size at metamorphosis and maturation, survival, propagule size, and fecundity. In this study I examined the tradeoff between egg size and clutch size in North Carolina populations of D. santeetlah, D. ocoee, and D. aeneus, with...

Across much of the globe, fire is a major disturbance agent of forest and grassland communities. The removal of fire from previously fire-maintained ecosystems, which has occurred in many areas, changes species composition, favoring later less fire tolerant species over fire-adapted ones. A recent measured increase in the rate of hybridization between the fire-adapted shortleaf pine (Pinus echinata) and less fire-adapted loblolly pine (P. taeda) suggests that introgression may be an emerging threat to shortleaf pine as a genetically distinct species. We used 25 microsatellite markers on...

The benefits and challenges of interdisciplinary training are well documented, and several reviews have discussed the particular importance of interdisciplinary training for conservation scholars and practitioners. We discuss the progress within one university program to implement specific training models, elements, and tools designed to move beyond remaining barriers to graduate-level, interdisciplinary conservation education.

Air pollution from diesel truck traffic travelling to and from port facilities is a major environmental health concern in areas of Philadelphia such as the Port Richmond neighborhood. Ambient monitoring has limited capability to assess neighborhood- or personal-level exposures to this pollution. We sought to conduct a pilot study using a community-based participatory research (CBPR) approach to assess community environmental health concerns, and measure residents' exposure to airborne traffic-related pollutants (fine particles [PM2.5]).

This paper summarizes the results of an update to a resource assessment, published in 2005, commonly referred to as the Billion-Ton Study (BTS). The updated results are consistent with the 2005 BTS in terms of overall magnitude. The 2005 BTS projected between 860 and 1240 Tg of biomass available in the 2050 timeframe, while the Billion-Ton Update (BT2), for a price of 66 $ Mg-
1, projected between 994 and 1483 Tg in 2030. For the BT2, forest residue biomass potential was determined to be less owing to tighter restrictions on forest residue supply including restrictions due to limited...

Wood as a material has unique properties that make it ideal for above ground exposure in a wide range of structural and non-strucutral applications. However, no material is without limitations. Wood is a bio-polymer which is subject to degradative processes, both abiotic and biotic. This chapter is a general summary of the abiotic and biotic factors that impact service life of wood in above ground exposures, and briefly discusses test methodologies commonly used in North America to determine the durability of wood and wood based materials in above ground exposure. Current efforts to...

Wood decay is a complex process that involves contributions from molds, bacteria, decay fungi, and often insects. The first step in the accurate diagnosis of decay is identification of the causal agents, but wood decay in the strictest sense (white and brown rot) is caused by cryptic fungal species that are very difficult to identify using traditional methods. Genetic methods offer fast, reliable, and accurate means to identify microbes from infected woody material. The purpose of this chapter is to summarize the available first generation DNA based techniques for identification of...

Current understanding of aspen fire ecology in western North America includes the paradoxical characterization that aspen-dominated stands, although often regenerated following fire, are “fire-proof”. We tested this idea by predicting potential fire behavior across a gradient of aspen dominance in northern Utah using the Forest Vegetation Simulator and the Fire and Fuels Extension. The wind speeds necessary for crowning (crown-to-crown fire spread) and torching (surface to crown fire spread) were evaluated to test the hypothesis that predicted fire behavior is influenced by the proportion...

This meeting was the 25th in a series of annual USDA Interagency Research Forums that are sponsored by the Forest Service, Animal and Plant Health Inspection Service, National Institute of Food and Agriculture, and Agriculture Research Service. The Group's original goal of fostering communication and providing a forum for the overview of ongoing research among the Agencies and their cooperators is being realized and facilitated through this meeting. This proceeding documents the efforts of many individuals: those who organized and sponsored the meeting, those who provided oral and poster...