Treesearch

Predicting species response to climate change is a central challenge in ecology, particularly for species that inhabit large geographic areas. The mountain pine beetle (MPB) is a significant tree mortality agent in western North America with a distribution limited by climate. Recent warming has caused large-scale MPB population outbreaks within its historical distribution, in addition to migration northward in western Canada. The relative roles of genetic and environmental sources of variation governing MPB capacity to persist in place in a changing climate, and the migratory potential at...

Dryland ecosystems play an important role in the global carbon cycle, including regulating the inter-annual global carbon sink. Dynamic global vegetation models (DGVMs) are essential tools that can help us better understand carbon cycling in different ecosystems. Currently, there is limited knowledge of the performance of these models in drylands partly due to characterizing the heterogeneity of the vegetation and hydrometeorological conditions. The aim of this study is to evaluate the performance of a DGVM for drylands to facilitate improved understanding of gross primary production (GPP)...

he Forest Products Laboratory (FPL), part of the USDA, in Madison, Wis., along with its new satellite laboratory in Starkville, Miss., have been involved in the examination and testing of wood preservative systems to improve durability of railroad ties and other wood products for the last 110 years. In keeping with the spirit of a pragmatic approach to research, FPL continues to devote a signifcant portion of its efforts toward applied research in wood preservation, often in collaboration with industry and university partners. In September of 2018, the FPL Starkville group partnered with...

Lignin is a multifunctional biopolymer with high application potential in the synthesis of thermoplastic materials. Industrial and investigational lignins have been incorporated into various commercial polymers, including biobased polymers, to improve their biodegradability, cost, and thermomechanical stability. Lignin is also expected to bring additional beneõts to the formulations, such as ôame retardancy, UV-protecting ability, and antioxidant and anti-weathering capacity. Strategies focused on lignin size reduction, fractionation, and modiõcation via esteriõcation, etheriõcation, and...

Cellulose is the most abundant biopolymer on Earth, found in trees, waste from agricultural crops and other biomass. The fibres that comprise cellulose can be broken down into building blocks, known as fibrillated cellulose, of varying, controllable dimensions that extend to the nanoscale. Fibrillated cellulose is harvested from renewable resources, so its sustainability potential combined with its other functional properties (mechanical, optical, thermal and fluidic, for example) gives this nanomaterial unique technological appeal. Here we explore the use of fibrillated cellulose in the...

The objective of this study is to examine the mechanical performance of cross laminated timber (CLT) panels made of low-value sugar maple under out of plane loads through mechanical tests and numerical simulation. The laminations were sorted into High and Low classes based on the measured modulus of elasticity (MOE). Two 3-layer sugar maple CLT layups as High-Low-High and Low-High-Low glued with resorcinol-based adhesive and one CLT layup of High-Low-High glued with melamine-based adhesive were prepared. Block shear, long-span bending (span-to-depth ratio of 33:1) and short-span bending...

Active wildfire seasons in the western U.S. warrant the evaluation of post-fire forest management strategies. Ground-based salvage logging is often used to recover economic loss of burned timber. In unburned forests, ground-based logging often follows best management practices by leaving undisturbed areas near streams called stream buffers. However, the effectiveness of these buffers has not been tested in a post-wildfire setting. This experiment tested buffer width effectiveness with a novel field-simulated rill experiment using sediment-laden runoff (25 g/L) released over 40 min at...

This chapter introduces the Global Forest Products Model (GFPM). The general model structure and the mathematical formulation of the GFPM are provided and key differences and similarities to the modeling approaches developed in the previous chapters are highlighted. The usefulness of the GFPM as a forest sector tool for policy analysis is illustrated by summarizing its applications in a wide array of past and ongoing studies. These studies are summarized under four representative groups: (i) forest sector outlook studies; (ii) studies evaluating the consequences of tariff and non-tariff...

In August, the U.S. housing market was mixed. Assessing the month-over-month data yielded increases for single-family starts and permits, housing under construction, new and existing house sales, and construction spending. On a year-over-year basis, most categories were positive, with the exceptions of multifamily starts, total and multifamily permits, and all completion categories. New house sales continued increasing, recording the largest sales number since 2006. Residential construction spending was positive month-over-month and year-over-year.

In September, most housing indictors were positive. Multifamily housing starts and permits were negative on month-over-month and year-over-year bases. Multifamily housing under construction and new house sales were negative on a month-over-month basis. Housing remains a bright spot for the U.S. economy