Treesearch

The objective of this study was to better understand changes in the hardwood lumber supply chain from the perspective of lumber producers and distributors and to assess the degree of judgmental convergence between suppliers and buyers of hardwood lumber. Results from two nationwide surveys conducted in 2008 and 2009 were used for the analysis. Findings confirmed a decline in demand for red oak and an increase in species diversity in the market, although a majority of sales were dominated by five species. Results also showed an increasing importance of markets for lower grades of lumber,...

This study investigated the effect of using extracted and delignified wood flour on water sorption properties of wood–plastic composites. Wood flour (WF) extraction was performed with three solvent systems: toluene/ethanol (TE), acetone/water (AW), and hot water (HW); delignification was conducted using sodium chlorite/acetic acid solution. A 24 full-factorial experimental design was employed to determine the effects of treatments and combinations of treatments. WF/HDPE composites for testing were manufactured using extrusion and injection molding. Compared with composites containing...

Modeled geospatial datasets have been created for 325 tree species across the contiguous United States (CONUS). Effective application of all geospatial datasets depends on their accuracy. Dataset error can be systematic (bias) or unsystematic (scatter), and their magnitude can vary by region and scale. Each of these characteristics affects the locations, scales, uses, and questions to which a dataset is best applied, and the risk involved in doing so. This study uses a suite of assessment metrics to characterize the type, magnitude, frequency, and spatial location of errors in this large...

The anaerobic decomposition of plant biomass is an important aspect of global organic carbon cycling. While the anaerobic metabolism of cellulose and hemicelluloses to methane and carbon dioxide are well-understood, evidence for the initial stages of lignin decomposition is fragmentary. The objective of this study was to look for evidence of chemical transformations of lignin in woody tissues [hardwood (HW), softwood (SW), and old newsprint (ONP)] after anaerobic decomposition using Klason and acid-soluble lignin, CuO oxidation, and 2D NMR. Tests were conducted under mesophilic and...

A significant portion of global carbon is sequestered in forest systems. Specialized fungi have evolved to efficiently deconstruct woody plant cell walls. These important decay processes generate litter, soil bound humic substances, or carbon dioxide and water. This chapter reviews the enzymology and molecular genetics of wood decay fungi, most of which are members of the Agaricomycotina subphylum. This chapter emphasizes recent advances derived from a growing number of genome resources but otherwise directs interested readers to previously published reviews for additional information....

Established by a conservation easement in 2006, Moro Big Pine Natural Area-Wildlife Management Area (MBP) encompasses ~16,000 contiguous acres in the pine flatwoods of southern Arkansas. This large-scale cooperative effort, focused on an ecosystem with high conservation value in a landscape increasingly dominated by planted, intensively managed loblolly pine (Pinus taeda), arose from an initiative by Potlatch Corporation, the State of Arkansas, and The Nature Conservancy (TNC). The MBP is a permanent easement purchased with a combination of public and private funds that seeks to balance...

Climate warming is projected to affect forest water yields but the effects are expected to vary.We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a...

The sources and oxidation pathways of atmospheric nitric acid (HNO3) can be evaluated using the isotopic signatures of oxygen (O) and nitrogen (N). This study evaluated the ability of Nylasorb nylon filters to passively collect unbiased isotopologues of atmospheric HNO3 under controlled and field conditions. Filters contained in passive samplers were exposed in continuous stirred tank reactors (CSTRs) at high (16 μg/m3) and moderate (8 μg/m3) HNO3 concentrations during 1–4 week deployment times. Filters were concurrently exposed at high and low N deposition sites along a gradient in the...

Mounting research highlights the contribution of ecosystem services provided by urban forests to quality of life in cities, yet these services are rarely explicitly considered in environmental policy targets. We quantify regulating services provided by urban forests and evaluate their contribution to comply with policy targets of air quality and climate change mitigation in the municipality of Barcelona, Spain. We apply the i-Tree Eco model to quantify in biophysical and monetary terms the ecosystem services "air purification," "global climate regulation," and the ecosystem disservice "air...

Studies linking genetic structure in amphibian species with ecological characteristics have focused on large differences in dispersal capabilities. Here, we test whether two species with similar dispersal potential but subtle differences in other ecological characteristics also exhibit strong differences in genetic structure in the same landscape. We examined eight microsatellites in marbled salamanders (Ambystoma opacum) from 29 seasonal ponds and spotted salamanders (Ambystoma maculatum) from 19 seasonal ponds in a single geographic region in west-central Massachusetts. Despite overall...