Treesearch

Biomass burning is known to contribute large quantities of CO2, CO, and PM2.5 to the atmosphere. Biomass burning not only affects the area in the vicinity of fire but may also impact the air quality far downwind from the fire. The 2007 and 2012 western U.S. wildfire seasons were characterized by significant wildfire activity across much of the Intermountain West and California. In this study, we determined the locations of wildfire-derived emissions and their aggregate impacts on Salt Lake City, a major urban center downwind of the fires. To determine the influences of biomass burning...

This report investigates the interactions between household location decisions and community characteristics, including green space. Household location decisions are a primary driver of land-use change, and collective location decisions affect community characteristics. At the same time, community characteristics affect location decisions. Neighborhoods or communities that have well-managed green space programs are more attractive to residents, a two-way interaction that tends to be self-reinforcing. Communities with high amenities and public services attract high-income residents,...

Stress in trees is caused by disturbances such as fire, flood, disease, or insect infestations. A single stressor may not be enough to kill a tree, but a combination can be deadly. Tree tissues produce and accumulate ethanol in response to many stressors. Ethanol provides the stressed tissues with an emergency energy source when their normal source of energy from aerobic respiration is impaired by stressors. Many insects, including various bark and ambrosia beetles, can detect ethanol. If the stressed tree releases enough ethanol into the atmosphere, it serves as a signal, attracting the...

The U.S. Forest Service, Northern Research Station has been conducting research on the silviculture of northern conifers on the Penobscot Experimental Forest (PEF) in Maine since 1950. Formal study plans provide guidance and specifications for the experimental treatments, but documentation is also needed to ensure consistency in data collection and sampling protocols. This guide details current sampling and measurement protocols for three of the longest running Forest Service experiments on the PEF: (1) the management intensity demonstration (1950 to present), (2) the compartment management...

Decision making to mitigate the effects of natural hazards is a complex undertaking fraught with uncertainty. Models to describe risks associated with natural hazards have proliferated in recent years. Concurrently, there is a growing body of work focused on developing best practices for natural hazard modeling and to create structured evaluation criteria for complex environmental models. However, to our knowledge there has been less focus on the conditions where decision makers can confidently rely on results from these models. In this review we propose a preliminary set of conditions...

Toxic organohalogen pollutants produced as byproducts of industrial processes, such as chloroform and polychlorinated dibenzo-p-dioxins, also have significant natural sources. A substantial terrestrial source of halogenated organics originates from fungal decay of wood and leaf litter. Here we show that the lignicolous basidiomycete Phellinus badius deposits up to 30,000 mg of the halogenated metabolite drosophilin A methyl ether (DAME, tetrachloro-1,4- dimethoxybenzene) per kilogram of decayed heartwood in the mesquite Prosopis juliflora. DAME occurs as clusters of glassy crystals up to 1...

Mixed office paper (MOP) pulp without deinking with an ash content of 18.1 ± 1.5% was used as raw material to produce nanofiller-paper. The MOP pulp with filler was mechanically fibrillated using a laboratory stone grinder. Scanning electron microscope imaging revealed that the ground filler particles were wrapped by cellulose nanofibrils (CNFs), which substantially improved the incorporation of filler into the CNF matrix. Sheets made of this CNF matrix were densified due to improved bonding. Specific tensile strength and modulus of the nanofiller-paper with 60-min grinding reached 48.4...

Documenting the environmental performance of building products is becoming increasingly common. Developing environmental product declarations (EPDs) based on life-cycle assessment (LCA) data is one way to provide scientific documentation. Many U.S. structural wood products have LCA-based “eco-labels” using the ISO standard. However, the standard requires underlying life-cycle inventory (LCI) data to be of recent age. This study updates the gate-to-gate manufacturing LCI data for laminated veneer lumber (LVL) for Pacific Northwestern (PNW) and for southeastern (SE) United States. Modeling...

Forest residue is one of the most cost-effective feedstock for biofuel production. It has relatively high bulk density and can be harvested year round, advantageous for reducing transportation cost and eliminating onsite storage. However, forest residues, especially those from softwood species, are highly recalcitrant to biochemical conversion. A severe pretreatment for removing this recalcitrance can result in increased sugar degradation to inhibitors and hence cause difficulties in fermentation at high solid loadings. Here, we presented high titer ethanol production from Douglas-fir...

Developing renewable energy sources with low environmental impacts is becoming increasingly important as concerns about consuming fossil fuel sources grow. Cultivating, harvesting, drying, and densifying raw biomass feedstocks into pellets for easy handling and transport is one step forward in this endeavor. However, the corresponding environmental performances must be quantified. This study presents cradle-to-gate life cycle inventory and impact assessment data for switchgrass fuel pellets potentially manufactured in the US Southeast. Because there are no current manufacturers of switchgra...