Treesearch

Nitrogen has been shown to be a limiting nutrient across a range of xylophagous insects. These insects often rely on symbiotic microorganisms in the gut for nitrogen acquisition, via fixation of atmospheric nitrogen or break down of other available nitrogenous substances. In phylogenetically lower, wood-feeding termites, the role of nitrogen fixing bacteria has been well studied. However, there is also evidence that uric acid can be metabolized into ammonia and serve as an additional nitrogen source. In this study, 36 Actinobacterial isolates (Streptomyces spp.) from the guts of Reticuliter...

We report the genome of Postia (Rhodonia) placenta MAD-SB12, a homokaryotic wood decay fungus (Basidiomycota, Polyporales). Intensively studied as a representative brown rot decayer, the gene complement is consistent with the rapid depolymerization of cellulose but not lignin.

The relationships between flame length, mass loss rate, and the Froude number have become well-established for many different fuels over the past 60 years. Chaparral, a mixture of shrub plants from the Mediterranean climate zone of southwestern North America, represents a fuel type—living plants—that has seldom been included in the development of these relationships. Flame length and mass loss data from single leaves to high bulk density fuel beds similar to wooden cribs were compared to existing correlations for circular and line burner configurations. Fuel moisture content of the fuels...

Nitrogen (N) additions have decreased species richness (S) in hardwood forest herbaceous layers, yet the functional mechanisms for these decreases have not been explicitly evaluated.We tested two hypothesized mechanisms, random species loss (RSL) and non-random species loss (NRSL), in the hardwood forest herbaceous layer of a long-term, plot-scale, fertilization experiment in the central Appalachian Mountains, USA. Using a random thinning algorithm, we simulated changes in species densities under RSL and compared the simulated densities to the observed densities among N-fertilized (+N),...

Cellulose nanocrystals (CNCs), produced from dissolving wood pulp, were chemically functionalized by transesterification with canola oil fatty acid methyl ester (CME). CME performs as both the reaction reagent and solvent. Transesterified CNC (CNCFE) was characterized for their chemical structure, morphology, crystalline structure, thermal stability, and hydrophobicity. Analysis by Fourier transform infrared (FTIR) and FT-Raman spectroscopies showed that the long chain hydrocarbon structure was successfully grafted onto CNC surfaces. After transesterification the crystal size and crystallin...

Extensive outbreaks of the emerald ash borer (Agrilus planipennis; EAB), an invasive forest insect, are having serious impacts on the cultural ecosystem services of urban forests in the United States and other countries. Limited experience with how such outbreaks might affect recreational opportunities prompted this investigation of visitors to a state park in St. Paul/Minneapolis, Minnesota, USA, where EAB damage is occurring. A photoquestionnaire solicited visitors' visual preferences for trail environments in a discrete choice experiment. Systematically manipulated digital images...

Stable carbon and nitrogen isotopes can be influenced by a multitude of factors including elevation, precipitation rate, season, and temperature. This work examined variability in foliar stable carbon (δ13C) and nitrogen (δ15N) isotope ratios of koa (Acacia koa) across 17 sites on Hawai'i Island, delineated by elevation and precipitation gradients. Sites were identified and grouped with respect to mean annual precipitation (MAP), mean annual temperature (MAT) and position along three elevation transects. Analysis of resultant δ13C and δ15N isotope ratios from multiple individuals across...

In this study, the changes in physical properties and preservative retention of high-grade plywood when subjected to artificial aging processes were examined. The plywood was 15/32-in.-thick panels manufactured from southern yellow pine A and C grades of veneer. The artificial aging processes consisted of three primary mechanisms of degradation: thermal degradation, hydrolysis, and swelling and shrinking stresses. Three aging processes of various severity were used. The least severe was cycled changes in ambient temperature and humidity. The second most severe was cycles of submersion and...

The spotted owl (Strix occidentalis) is one of the most studied raptors in the world (Lõmus 2004) because forest management throughout its range has the potential to negatively affect owl populations. Information on the California spotted owl (S. o. occidentalis) has been summarized in several literature reviews (e.g., Gutiérrez 1996; Gutiérrez and Carey 1985; Gutiérrez et al. 1995; Keane 2014; Roberts and North 2012; USFWS 1990, 1993, 2003, 2006; Verner et al. 1992a). However, the first comprehensive review of the biology of the California spotted owl was conducted by Verner et al....