Treesearch

The objective of this study was to determine the technical feasibility of combining acousticwave data with high-resolution laser scanning data to improve the accuracy of defect detection and quality assessment in hardwood logs. This article (Part 1) focused on exploring the potential of an acoustic impact testing method coupled with advanced waveform analysis to detect internal decay of hardwood logs and classify logs in terms of log quality and potential board grade yields. Twenty-one yellow-poplar (Liriodendron tulipifera)logs obtained from the Central Appalachian region were evaluated...

Durability of wood products intended for use in outdoor aboveground applications are evaluated using one or more standardized test methods. These methods use relatively small specimens in an effort to accelerate decay growth and allow detection of decay. In this study, we evaluated internal moisture content and temperature of standardized specimens and compared them with specimens of a simulated post and beam connection that is recommended for residential deck construction. Specimens of each type were cut from end-matched Southern Pine timbers and exposed above ground at a test site near...

This research focused on evaluating the bending stiffness and strength of structural lumber with transverse vibration nondestructive testing techniques. A random sample of nominal 2-in.- (standard 38-mm-) thick Southern Pine dimension lumber was obtained from several mills in southeastern United States. After conditioning, the lumber specimens were nondestructively tested using transverse vibration techniques. Modulus of elasticity (MOE) was determined using the frequency of oscillation and density. Static bending MOE and strength were then determined for each specimen. Statistical...

Short-rotation woody crops in the southeastern United States will make a significant contribution to the growing renewable energy supply over the 21st century; however, there are few studies that investigate how species selection may affect water yield. Here we assessed the impact of species selection on annual and seasonal water budgets in unvegetated plots and late-rotation 14–15-year-old intensively managed loblolly pine (Pinus taeda L.) and sweetgum (Liquidambar styraciflua L.) stands in South Carolina USA. We found that while annual aboveground net primary productivity and bioenergy...

We conducted this assessment to provide information on the current conditions of riparian and wetland ecosystems in reference to their natural range of variation on the Ashley National Forest during Forest Plan revision. We determined that riparian and wetland ecosystems have experienced numerous stressors that have influenced their current conditions, including reduced beaver activity, altered flow regimes, dams and diversions, livestock and wild ungulate grazing, and climate change. Some ecosystem characteristics, particularly channel and floodplain dynamics, appear to be more resistant...

Clouds and cloud shadows block land surface information in optical satellite images. Accurate detection of clouds and cloud shadows can help exclude these contaminated pixels in further applications. Existing cloud screening methods are challenged by cloudy regions where most of satellite images are contaminated by clouds. To solve this problem for landscapes where the typical frequency of cloud-free observations of a pixel is too small to use existing methods to mask clouds and shadows, this study presents a new Automatic Time-Series Analysis (ATSA) method to screen clouds and cloud...

The ground flora stratum affects stand structure, resource acquisition, nutrient cycling, and taxonomic richness in forest ecosystems. Disturbances such as thinning and prescribed fire alter forest understory growing conditions that generally increase ground flora cover and richness. We studied annual changes in ground flora assemblages over three growing seasons after fire in thinned and frequently burned (3-year rotation) Pinus-Quercus stands. Our results corroborated trends from other studies that indicated greater ground flora richness and cover after thinning and burning compared with...

Forest insect and pathogen outbreaks may exacerbate anthropogenic climate change if they accelerate soil carbon loss to the atmosphere. We quantified soil respiration and carbon content for nearly a decade after girdling or natural infestation of hemlock (Tsuga canadensis L. Carr., a codominant species in southern Appalachian forests) by hemlock woolly adelgid (Adelges tsugae) to improve understanding of soil carbon response to disturbance from forest insect and pathogens. From 2005 to 2013, net soil respiration was similar among hemlock mortality (~50% basal area reduction) and reference...

Interactions between climate and ecosystem properties that control phenological responses to climate warming and drought are poorly understood. To determine contributions from these interactions, we used space-borne remotely sensed vegetation indices to monitor leaf development across climate gradients and ecoregions in the southeastern United States. We quantified how air temperature, drought severity, and canopy thermal stress contribute to changes in leaf flushing from mountainous to coastal plain regions by developing a hierarchical state-space Bayesian model. We synthesized daily...

Natural resources across the United States are increasingly managed at the landscape scale through cooperation among multiple organizations and landowners. United States Department of Agriculture Forest Service (USFS) agency leaders have widely promoted this approach since 2009 when Secretary of Agriculture Vilsack called for "all lands" management. Landscape scale projects have been undertaken to address multiple goals such as single species conservation, resilience to fire, invasive species eradication, and others. The West Virginia Restoration Venture (WVRV)—one of five landscape scale...