Treesearch

Cellulose nanomaterials (CNMs) are a class of materials that have recently garnered attention in felds as varied as structural materials, biomaterials, rheology modifers, construction, paper enhancement, and others. As the principal structural reinforcement of biomass giving wood its mechanical properties, CNM is strong and stif, but also nontoxic, biodegradable, and sustainable with a very large (Gton yr−1 ) source. Unfortunately, due to the relatively young nature of the feld and inherent incompatibility of CNM with most man-made materials in use today, research has tended to be more...

The performance of cellulosic materials is intimately linked to their moisture content. Over the last century, many studies have been devoted to examining the moisture uptake in equilibrium with surrounding environmental conditions. However, with the adoption of automated sorption balances in laboratories worldwide, it has become increasingly popular to study the approach to equilibrium, i.e., sorption kinetics. Recording the moisture content change between two equilibrium states produces a wealth of data, which necessitates a robust methodology for analysis. In this study, we employ...

Loblolly pine is a major fibre source for the pulp and paper industry. Herewe developed the first nonlinear models to predict the within-tree and regional variation of tracheid length and width for planted loblolly pine. Data were obtained from macerated tracheids and near-infrared spectroscopy calibration models from trees sampled in 109 stands across the southeastern United States. The fixed effects for the final tracheid length model, which included cambial age, height of disk within tree, and physiographic region, explained 71 percent of the variation with root mean square error (RMSE)...

Burgundy oil (BO) from Eastern red cedar provides resistance against termites and wood-decay fungi and is enhanced when combined with an amylose inclusion complex (AIC) containing hexadecylammonium chloride (HAC). Indirect evidence also indicated that a methanol Loblolly pine extract (LPE) was inhibitory against termites. This study compared the effects of HAC and didecyldimethylammonium chloride (DDAC) combined with LPE and BO on termites and wood-decay fungi. Southern pine was treated by vacuum/pressure impregnation and resistance evaluated after exposure to termites and decay fungi. The...

Through their multiple functions, refuges may be important for stream-living fishes, particularly during stressful events such as seasonal low flow or drought. Coastal Cutthroat Trout Oncorhynchus clarkii clarkii is an ideal study organism to understand the importance of refuge. During seasonal low flow, lower water levels limit access to refuge and emigration, survival of fish is low, and predation risk is high. Under these conditions, we studied patterns of cover use from field observations and tested predictions from multiple hypotheses about cover use in a semi-natural experiment....

Reactive nitrogen (Nr) within smoke plumes plays important roles in the production of ozone, the formation of secondary aerosols, and deposition of fixed N to ecosystems. The Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen (WE-CAN) field campaign sampled smoke from 23 wildfires throughout the western U.S. during summer 2018 using the NSF/NCAR C-130 research aircraft. We empirically estimate Nr normalized excess mixing ratios and emission factors from fires sampled within 80 min of estimated emission and explore variability in the dominant forms of Nr...

Purpose Producing biochar from forest residues can help resolve environmental issues by reducing forest fires and mitigating climate change. However, transportation and storage of biomass to a centralized facility are often cost-prohibitive and a major hurdle for the economic feasibility of producing biobased products, including biochar. The purpose of this study was to evaluate the environmental impacts and economic feasibility of manufacturing biochar from forest residues with small-scale portable production systems. Methods This study evaluated the environmental performance and...

A summer storm passes, flashing lightning but little rain and a fire starts to grow. Flames lick the bases of trees, charring stems and strong winds fan the fire at times, causing the flames to scorch foliage, as it burns through a forest. The fate of these burned trees after the flames are doused is one of intense interest. Will the forest become a carbon source? Will there be suitable wildlife habitat? Will enough trees survive to perpetuate and regenerate the forest? Are the trees now more vulnerable to bark beetle attacks or drought? To answer these questions, ecologists are reliant on...

Black spruce (Picea mariana) peatlands play important ecologic and economic roles in the temperate-boreal region of North America, providing a valuable timber resource while also performing important ecosystem functions. Climate models project decreases in the amount of snowfall received throughout the temperate-boreal region by 2100, as average wintertime temperatures increase. We used a paired-plot experimental design to assess the effect of snow removal on soil temperature and frost development at six forested peatland sites in northern Minnesota, USA, during the three winters from 2017...

A scientific consensus is building that the drawdown of very large amounts (at least 1,000 Gt [1.1 x 1012 tn]) of carbon dioxide (CO2) from the atmosphere will be needed to stabilize the earth’s climate system at a safe temperature (Hansen et al. 2008; Cao and Caldeira 2010; IPCC 2018, 2019). The minimum estimated cost of this drawdown is tens of trillions of dollars over the course of a century and ultimately will depend on the total amount of fossil carbon (C) emitted by humankind (emissions must be reduced as quickly as possible to make any drawdown effective). The cost of drawdown,...