Treesearch

Determining the extent of soil property changes following forest management activities (e.g., timber harvest, fuels abatement, site preparation) is an ongoing concern for land managers. Monitoring the long-term effects of various harvest operations and fuels treatment methods on soil physical properties and hydrologic function is critical to maintaining forest productivity. We document changes in detrimental soil disturbance (DSD) in harvest units located on the Kootenai National Forest that occurred over two decades. From 1992 through 2006, 251 harvest units on the Kootenai National...

This study explored the consequences for long-term projections and impact analysis of the uncertainty in model parameters and initial conditions. Using the Global Forest Products Model, multiple replications of projections were carried out with parameters or initial condition data sampled randomly from their assumed distribution. The results showed that parameter uncertainty led to uncertainty of the projections increasing steadily with the time horizon, and more rapidly than the uncertainty stemming from initial conditions. Among the parameter uncertainties, those in the supply and demand...

The objectives of this study were to investigate the wear behavior of drill bits in wood drilling resistance measurements and to understand how the blunting of the cutting edges may affect the cutting forces and ultimately the measurement results. Laboratory resistance drilling experiments were conducted using an IML-RESI PD 400 tool (IML Instrumenta Mechanik Labor GmbH, Wiesloch, Germany) and a standard spade-type drill bit. Results were based on 375 drillings made on a 2.58 m long, freshly cut, defect-free yellow birch (Betula alleghaniensis) log with an average MC of 55.5%, an average...

The objective of this study was to determine the technical feasibility of combining acoustic wave data with high-resolution laser scanning data to improve the accuracy of defect detection and quality assessment in hardwood logs. Using acoustic impact testing and high-resolution laser scanning techniques, 21 yellow poplar logs (Liriodendron tulipifera) obtained from the central Appalachian region were evaluated for internal and external defects. These logs were then sawn into boards and the boards were visually graded based on the National Hardwood Lumber Association grading rules. The...

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...