Treesearch

To meet newer environmental standards, modified plant proteins have been studied as no-added formaldehyde wood adhesives for interior applications. Many methods have been developed to increase the wet strength of wood products bonded with soy adhesives. These methods involve modifying the soy in separate steps prior to formulating the adhesive or adding a polymerizable co-reactant to the soy. We show that adding periodate, permanganate, or iodate to soy flour improved the strength of soy adhesive bonds in small-scale testing and in plywood shear, especially when tested under wet conditions....

Recently, measured flame spread indices on commercial wood species tested per ASTM E84 were found to be lower than previously published data. One reason for this may be that the hygrothermal conditioning of the red oak calibrant required by the test standards for measuring flame spread was changed between 1973 and 1981. This paper examines how much variability there is in the moisture content of commercially important wood species at 50% relative humidity by collecting water vapor sorption isotherms. Additionally, the effect of moisture content on the flame spread was evaluated after...

This article reports on the development of accelerated laboratory methods to allow estimation of preservative leaching frompressure-treated wood exposed to precipitation. End-matched lumber specimens were pressure-treated with a boron–copper formulation and exposed to natural weathering for 1 yr, laboratory immersion protocols, or a laboratory-simulated rainfall protocol. The rainfall runoff or immersion water was collected at intervals according to the method used and analyzed for concentrations of copper and boron. Of the laboratory methods evaluated, the simulated rainfall approach...

Populus species have a high productivity potential as short-rotation woody crops, provided that site-suitable varieties are planted. The Coastal Plain, the Piedmont, and the Blue Ridge Mountains make up a significant part of the eastern and southeastern USA, and an insight into poplar productivity and adaptability will be valuable for the successful implementation of large-scale poplar stands in these regions. The objectives of this study were to examine the green wood biomass (hereafter biomass), biomass allocation, and wood properties of poplars in relation to growing conditions,...

Bark and woodboring beetles include some of the most economically important forest pests. Understanding how these species are distributed in forests is critical for optimizing detection strategies. We placed traps at three heights above ground level at the edge and in the interior of two forests and focused on two groups: phloem/wood-feeding beetles (Coleoptera: Buprestidae, Cerambycidae, and some Curculionidae: Scolytinae) and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae and Platypodinae). We recorded temperature, humidity, and canopy cover for each trap. Species richness...

With future global temperatures predicted to increase, the relationship between a host, pathogen, and environment, becomes less predictable and epidemics may pose a greater risk to forests worldwide. Resistance breeding is an important disease management tool, but because tree species require long breeding times, it is necessary to develop techniques for testing current pathogen isolates against their hosts. Pitch canker disease of pines, caused by the pathogen Fusarium circinatum, is no exception and represents a threat to pine forests and commercial plantations worldwide, as it thrives...

Scientific knowledge and tools have central roles in contemporary federal forest programs that promote restoration in large landscapes and across ownerships. Although we know much about the role of science in decisionmaking and ways that science can be better linked to practice, we know less about manager perspectives about science and science tools, and the perceived role of both in planning. We surveyed Forest Service resource managers in the western United States to address this knowledge gap. Respondents engaged most frequently with science via reading research publications; direct...

Root disease caused by Armillaria mexicana and/or A. mellea is associated with tree mortality in peach (Prunus persica) orchards within their primary production zone of the Mexican sub-tropics. To improve management options for this disease, the resistance/susceptibility reactions of three Prunus rootstocks to infection by A. mexicana (isolate MEX85) and A. mellea (isolate MEX100) were evaluated under greenhouse and field conditions. Greenhouse phase: A. mexicana and A. mellea were independently inoculated on 14 trees (10-month old) of each rootstock in polycarbonate containers: P....

Wildland firefighters are exposed to wood smoke, which contains hazardous air pollutants, by suppressing thousands of wildfires across the U. S. each year. We estimated the relative risk of lung cancer and cardiovascular disease mortality from existing PM2.5 exposure-response relationships using measured PM4 concentrations from smoke and breathing rates from wildland firefighter field studies across different exposure scenarios. To estimate the relative risk of lung cancer (LC) and cardiovascular disease (CVD) mortality from exposure to PM2.5 from smoke, we used an existing exposure-respons...

Background: Fire is an important disturbance that influences species composition, community structure, and ecosystem function in forests. Disturbances such as hurricanes and landslides are critical determinants of community structure to Caribbean forests, but few studies have addressed the effect of paleofire disturbance on forests in Puerto Rico, USA. Soil charcoal is widely used to reconstruct fire history. However, the occurrence and frequency of paleofire can be underestimated due to charcoal decay. Results: We reconstructed the fire history of subtropical dry forests of Puerto Rico...