Treesearch

Biological invasions of native forests by nonnative pests result from complex stochastic processes that are difficult to predict. Although economic optimization models describe efficient controls across the stages of an invasion, the ability to calibrate such models is constrained by lack of information on pest population dynamics and consequent economic damages. Here we describe economic approaches for analyzing pre-invasion and post-invasion management of biological invasions under conditions of risk and uncertainty and emphasize the need for new microeconomic and aggregate studies of...

Resource selection by animals influences ecological processes such as dispersal, reproduction, foraging, and migration. Little information exists regarding foraging resource selection by bats during the maternity season. We evaluated support for effects of landcover type, landform, and landscape pattern on resource selection by individual foraging female eastern red bats (Lasiurus borealis) during the maternity period and compared resource utilization for all individuals pooled (population level), individuals grouped by geographic location, and individuals grouped by stage of lactation...

Understanding the impacts of disturbances in forest ecosystems is essential for long-term biodiversity conservation. Many studies have evaluated wildlife responses to various disturbances but most generally do not use changes in microclimate features or crohabitat structure to explain these responses. We examined lizard responses to two common forest management practices prescribed burning and thinning) in pine-hardwood forests of the Bankhead National Forest, Alabama, USA. Over 4 years, we captured 719 individual lizards representing seven species. Lizards exhibited species-specific...

United States (U.S.) hardwood log and lumber exports surged in the early- and mid-1970s in response to the adoption of floating exchange rates. However, assessing these changes in international trade became difficult in the 1980s due to increased underreporting of hardwood lumber and log shipments between the U.S. and Canada. By 1990, these data problems were rectified, allowing 1990 to be the earliest starting point for any analysis of hardwood lumber or log trade. The complements to hardwood lumber and log exports are hardwood imports for domestic consumption. U.S. hardwood lumber and...

The substitution of forest-derived woody biofuels for fossil fuel energy has garnered increasing attention in recent years, but information regarding the mid- and long-term effects on soil productivity is limited. We investigated 15-yr temporal trends in forest floor and mineral soil (0-30 cm) C and N pools in response to organic matter removal treatments (OMR; stem-only harvest, SOH; whole-tree harvest, WTH; and whole-tree plus forest floor removal, FFR) at three edaphically distinct aspen (Populus tremuloides Michx. and P. grandidentata Michx.) forests in the Great Lakes region. The OMR...

Trends in housing and other construction-related sectors continue to have a significant impact on the wood products industry, particularly cabinetry, furniture, millwork and components. This fifth annual survey assesses the market conditions for secondary woodworking manufacturers involved in construction-based sectors and includes information on their status and activities, as well as analysis of what has changed since last year. Conducted in early 2014, the study is a joint effort by Virginia Tech, the U.S. Forest Service and Wood Products.

Several social theories have been proposed to explain the uneven distribution of vegetation in urban residential areas: population density, social stratification, luxury effect, and ecology of prestige. We evaluate these theories using a combination of demographic and socio-economic predictors of vegetative cover on all residential lands in New York City. We use diverse data sources including the City's property database, time-series demographic and socio-economic data from the US Census, and land cover data from the University of Vermont's Spatial Analysis Lab (SAL). These data are...

Current theory in disturbance ecology predicts that extreme disturbances in rapid succession can lead to dramatic changes in species composition or ecosystem processes due to interactions among disturbances. However, the extent to which less catastrophic, yet chronic, disturbances such as wind damage and fire interact is not well studied. In this study, we simulated wind-caused gaps in a Pinus taeda forest in the Piedmont of north-central Georgia using static winching of trees to examine how wind damage may alter fuel characteristics and the behavior of subsequent prescribed fire. We found...

Structural properties have been shown to be critical in the osteoconductive capacity and strength of bioactive ceramic bone scaffolds. Given the cellular foam-like structure of bone scaffolds, nanoindentation has been used as a technique to assess the mechanical properties of individual components of the scaffolds. Nevertheless, nanoindents placed on scaffolds may violate the rigid support assumption of the standard Oliver–Pharr method currently used in evaluating the Meyer hardness, H, and elastic modulus, Es, of such structures. Thus, the objective of this research was to use the...