Treesearch

Five full-scale fire experiments were conducted to observe the performance of a two-level apartment-style structure constructed of mass timber. Each level consisted of a one bedroom apartment, an L-shaped corridor, and a stairwell connecting the two levels. One of the primary variables considered in this test series was the amount and location of exposed mass timber. The amount of mass timber surface area protected by gypsum wallboard ranged from 100% to no protection. For each experiment, the fuel load was identical and the fire was initiated in a base cabinet in the kitchen. In the first...

Secondary forests account for more than half of tropical forests and represent a growing carbon sink, but rates of biomass accumulation vary by a factor of two or more even among plots in the same landscape. To better understand the drivers of this variability, we used airborne lidar to measure forest canopy height and estimate biomass over 4529 ha at Serra do Conduru Park in Southern Bahia, Brazil. We measured trees in 30 georeferenced field plots (0.25-ha each) to estimate biomass using allometry. Then we estimated aboveground biomass density (ABD) across the lidar study area using a...

The invention of the Gutenberg printing press in 1440 started a steady increase in demand for paper. Until the mid-1800s, most paper pulp was made by collecting, cleaning, and beating discarded linen and cotton rags. Collection of rags was such a large and organized industry that companies were regulated by the government and workers had unions. Henry Mayhew described a grand banquet of the fraternal order of chiffonniers (rag-pickers).1 As literacy and printing technology improved, demand for paper outstripped supply, and the search for alternative sources of fiber began in earnest. For...

Peroxidases are considered essential agents of lignin degradation by white-rot basidiomycetes. However, low-molecularweight oxidants likely have a primary role in lignin breakdown because many of these fungi delignify wood before its porosity has sufficiently increased for enzymes to infiltrate. It has been proposed that lignin peroxidases (LPs, EC 1.11.1.14) fulfill this role by oxidizing the secreted fungal metabolite veratryl alcohol (VA) to its aryl cation radical (VA ), releasing it to act as a one-electron lignin oxidant within woody plant cell walls. Here, we attached the fluorescent...

Thousand Cankers Disease (TCD) of Juglans and Pterocarya (Juglandaceae) involves a fungal pathogen, Geosmithia morbida, and a primary insect vector, Pityophthorus juglandis. TCD was described originally from dying Juglans nigra trees in the western United States (USA), but it was reported subsequently from the eastern USA and northern Italy. The disease is often difficult to diagnose due to the absence of symptoms or signs on the bark surface of the host. Furthermore, disease symptoms can be confused with those caused by other biotic and abiotic agents. Thus, there is a critical need for a...

There is little published scientific literature on the laboratory or field testing of wood-plastic composites (WPC) against termite attack. Therefore, the objective of this research was to investigate termite resistance (both laboratory and field) of 5 different extruded WPC blends of 50% western pine wood flour (WF) and high-density polyethylene (HDPE), and untreated pine solid wood. The study included two unmodified control WPC blends (one with cut surfaces and one with plastic rich surfaces); one blend with 3% coupling agent (maleated polyethylene, MAPE); one blend with acetylated WF;...

Improved methods are needed to improve the reliability and reporting of Berkovich probe calibrations. Current methods for calibrating machine compliance rely substantially on the subjectivity of the user to choose and exclude from the analysis nanoindentations below a threshold size that are affected by probe tip imperfections or the fused silica surface properties. Furthermore, it can be difficult to identify erroneous experimental data, such as those resulting from dirty or damaged probes. To help overcome these issues in Berkovich probe calibrations, a pre-nanoindentation liftoff...

Since the early 1900s, a number of parasitoids have been released for classical biological control of the introduced destructive forest insect, Lymantria dispar (gypsy moth), in North America. During this time, two pathogens were accidentally introduced. These pathogens and several of the parasitoid species are now commonly found in North American gypsy moth populations. The aim in creating this guide was to provide laboratory techniques for distinguishing between two common pathogens, the fungus Entomophaga maimaiga and the gypsy moth multiple nucleopolyhedrovirus, and provide illustration...

Extreme flood events can substantially affect riverine systems, modifying instream habitat and influencing fish assemblages and densities. Rare species are especially vulnerable to these disturbance events because of their small population size and often reduced phenotypic heterogeneity. In June 2016 the lower Elk River in West Virginia experienced severe flooding, resulting in a peak discharge that exceeded the 0.005 annual exceedance probability (>200 y flood) in the main stem. We obtained pre-flood and postflood population count data and estimated abundances for one cohort of the...

Forest restoration, fuel reduction, and wildlife conservation management requires understanding if, and how repeated prescribed fire, fire severity, or mechanical methods can promote goals. We examined breeding bird response to repeated fuel reduction treatments by mechanical understory reduction (twice; Mechanical-only), prescribed burning (four times; Burn-only), or mechanical understory reduction plus burning (then three subsequent burns; Mechanical+Burn). Initial burns were hotter in Mechanical+Burn than Burn-only resulting in heavy tree mortality, canopy openness, thick shrub density,...