Treesearch

Novel hosts may have unforeseen impacts on herbivore life history traits. The mountain pine beetle (Dendroctonus ponderosae Hopkins) is a tree-killing bark beetle native to western North America but constrained by cold temperatures in the northern limits of its distribution. In recent years, this insect has spread north and east of its historical range, and continued expansion, or accidental introduction, could result in the mountain pine beetle becoming invasive in eastern North America. The limiting effect of cold temperatures among novel host pines is unknown, yet crucial for understandi...

Vibration can occur in wood floor systems as a consequence of a variety of human activities, ranging from common daily movements associated with individuals living in homes to high-intensity activities associated with sporting events that are held in large sports arenas. For example, the potential for harvesting energy from a wooden floor system in public buildings during daily rush hours could be substantial. In this pilot study, an energy harvesting system was developed to investigate the feasibility of harvesting energy from a vibrating wooden floor system. The purpose of this publicatio...

This report summarizes the third cycle of annualized inventory of Pennsylvania with field data collected from 2009 through 2014. Pennsylvania has 16.9 million acres of forest land dominated by sawtimber stands of oak/hickory and maple/beech/birch forest-type groups. Volumes continue to increase as the forests age with an average of 2,244 cubic feet per acre on timberland. Sawtimber volume has risen 24 percent in 10 years to 115 billion board feet. Net growth outpaced removals by a ratio of 2.4:1 on timberland. Additional information on land-use change, fragmentation, ownership, forest...

Invasive species know no boundaries; they spread regardless of ownership, and actions by neighboring landowners can influence local and regional populations and impacts. Native Americans and mainstream Western society (representing the prevalent attitudes, values, and practices of US society) both depend on forests for food, fiber, and emotional well-being, but in different ways. We surveyed Native American and nontribal environmental leaders in California to gauge differences in importance, impacts, and control strategies for invasive species and management of forest health. There were...

The walnut twig beetle, Pityophthorus juglandis Blackman, and associated fungus Geosmithia morbida Kolarık, Freeland, Utley, & Tisserat constitute the insect–fungal complex that causes thousand cankers disease in walnut, Juglans spp., and wingnut, Pterocarya spp. Thousand cankers disease is responsible for the decline of Juglans species throughout the western United States and more recently, the eastern United States and northern Italy. We examined the flight capacity of P. juglandis over 24-h trials on a flight mill in the laboratory. The maximum total flight distance observed was ~3.6 km...

Emerald ash borer is an invasive beetle causing significant mortality of ash trees (Fraxinus spp.) in North America and western Russia. The invasive range has expanded to more than half of the states in the United States since the initial detection in Michigan, USA in 2002. Emerald ash borer is typically managed with a combination of techniques including surveys/trapping, insecticide treatments, host tree removal, biological control, and public education/outreach. The insect's rapid spread rate and cryptic life history and a lack of resistance among most North American Fraxinus spp. have...

Non-native species invasions, growing human populations, and climate change are central ecological concerns in tropical island communities. The combination of these threats have led to losses of native biota, altered hydrological and ecosystem processes, and reduced ecosystem services. These threats pose complex problems to often underfunded management entities. We developed a watershed decision support tool (WDST) for the windward coast of Hawai‘i Island aimed at prioritizing catchments for invasive species removal and native forest protection from non-native species invasions. Using the...

The polymeric angle and concentration within the S2 layer of the softwood fiber cell wall are very critical for molecular and microscopic properties that influence strength, stiffness and acoustic velocity of wood at the macroscopic level. The main objective of this study was to elucidate the effect of cellulose, hemicellulose, lignin, microfibril angle and density on acoustic velocity and material mechanical properties of 14-year-old suppressed loblolly pine. Cellulose, hemicellulose and density are consistently the most important drivers of strength, stiffness and velocity. Cellulose and...

Financial enhancement of biomass value prior to pulping requires subsequent use of remaining materials; e.g., high value use of remaining stock material after cellulosic ethanol production would improve the economics for cellulosic ethanol. In this work, use of enzymatic hydrolysis residual solids (EHRS), a cellulosic ethanol byproduct, were investigated as a bulking agent. The study examined the effect across several grammages, 20 g/m2 -200 g/m2, and EHRS substitution levels, 10%, 15%, and 20%. EHRS retention was examined with light scattering. EHRS loading increased bulk while reducing...

Although X-ray diffraction (XRD) has been the most widely used technique to investigate crystallinity index (CrI) and crystallite size (L200) of cellulose materials, there are not many studies that have taken into account the role of sample moisture on these measurements. The present investigation focuses on a variety of celluloses and cellulose containing materials—from loblolly pine wood to tunicin, and evaluated moisture-induced changes in CrI and L200. It was observed that upon introduction of a small amount of water (5%) into P2O5 dried samples, for most samples, both absolute...