Treesearch

Emerald ash borer (EAB), a beetle from Asia that feeds on ash trees, was discovered as the cause of extensive ash mortality in southeast Michigan and adjacent areas of Canada in 2002. It is thought that this destructive pest was introduced in the early 1990's in infested solid wood packing material originating in Asia. Shortly after EAB was discovered in North America, federal and state regulatory agencies placed infested counties under quarantine and eradication activities were initiated. Due to the magnitude of the EAB infestation in North America, the potential for natural and artificial...

The percolation model developed by Zelinka et al. was based upon macroscale measurements of the electrical conductivity and implicitly treats the wood material as homogenous. The transport mechanism proposed by Jakes et al. depends upon a moisture induced glass transition occurring in the hemicelluloses. This theory suggests that there are likely differences in the threshold moisture content for moisture transport between different regions in the cell wall. For instance, the secondary cell wall contains cellulose microfibrils, amorphous cellulose, hemicelluloses, and lignin, where hemicellu...

Future use of woody biomass to produce electric power in the U.S. North can have an important influence on timber production, carbon storage in forests, and net carbon emissions from producing electric power. The Northern Forest Futures Project (NFFP) has provided regional- and state-level projections of standing forest biomass, land-use change, and timber harvest, which all influence forest contributions to global carbon cycles. This study supports the NFFP study of global carbon cycles by estimating potential local woody biomass supply under alternate procurement regimes and associated...

X-ray densitometry is a technique often used in tree growth and wood quality studies to incrementally measure density (specific gravity) along a radial strip of wood. Protocols for this technique vary between laboratories because of differences in species, equipment, tree age, and other factors. Here, the application of X-ray densitometry is discussed in terms of a case study specific to the southern pines, whereby loblolly (Pinus taeda L), longleaf (Pinus palustris Mill.), and slash (Pinus elliottii Engelm.) pine wood cores were analyzed using an automated system. Objectives of this study...

This paper reports the results of a search to discover the most cost effective and robust method of detecting Reticulitermes flavipes infestations in structural members of remote bridges, homes and other wooden structures and transmitting these results to internet cloud storage thus obviating routine travel to these structures for periodic visual inspections. Duplicate stainless steel tanks were constructed for housing R. flavipes colonies and commodity size dimension lumber members. Overall, results indicated that the simplest and cheapest independent variables to measure and send were:...

Epoxy printed circuit boards are used in a variety of electronics applications as rigid, thermally stable substrates. Due to the propensity of components on the boards, such as batteries and interconnects, to fail and ignite the epoxy, flame retardant additives are required to minimize fire risk. Currently, industry uses brominated flame retardants, such as TBBPA, to meet regulatory requirements1. However, recently, a number of environmental and human health issues have been raised about brominated compounds, so there is a desire to develop alternative flame retardant chemistries

Bioclimate models incorporating topographic predictors as surrogates for microclimate effects are developed for Populus tremuloides and Picea engelmannii to provide the fine-grained specificity to local terrain required for adapting management of three Colorado (USA) national forests (1.28 million ha) and their periphery to climate change. Models were built with the Random Forests classification tree using presence - absence observations obtained by overlaying species distribution maps on data points gridded at ~225 m within the forests and from ground plot observations from adjacent...

Human activity in the last century has led to a significant increase in nitrogen (N) emissions and deposition (Galloway et al. 2004). Total N emissions in the United States have increased significantly since the 1950s (Galloway 1998, Galloway et al. 2003). As S deposition has declined in response to regulation, the rate of N deposition relative to S deposition has increased since the 1980s (Driscoll et al. 2001, 2003) followed by a general decrease in NOx emissions from electric utilities since the early 2000s. More recently, the relative proportion of NHx (NH4+ + NH3 ) to NOx (NO + NO2)...

How does tree species composition vary in relation to geographical and environmental gradients in a globally rare tropical/subtropical broadleaf dry forest community in the Caribbean? We analyzed data from 153 Forest Inventory and Analysis (FIA) plots from Puerto Rico and the U.S. Virgin Islands (USVI), along with 42 plots that we sampled in the Bahamian Archipelago (on Abaco and Eleuthera Islands). FIA data were collected using published protocols. In the Bahamian Archipelago, we recorded terrain and landscape variables, and identified to species and measured the diameter of all stems C5...

This publication is an additional source of metadata for data stored and publicly available in the U.S. Department of Agriculture, Forest Service Research Data Archive. Here, we document the development, design, management, and operation of the experiment. In 1998, a team of scientists from the U.S. Forest Service, Department of Energy (DOE), Michigan Technological University, and several other institutions initiated the Aspen Free Air CO2 and Ozone Enrichment (Aspen FACE) Experiment. Using technology developed at DOE's Brookhaven National Laboratory (BNL), the experiment fumigated model...