Treesearch

In recent years, advances in molecular genetics have provided powerful tools to address critical issues in forest pathology to help promote resilient forests. Although molecular genetic tools are initially applied to understand individual components of forest pathosystems, forest pathosystems involve dynamic interactions among biotic and abiotic components of the environment. More sophisticated and holistic molecular genetic approaches are now available to better understand dynamic interactions of forest pathosystems. This presentation will describe how advanced molecular genetic technologi...

Summary The first wildfires in sudden oak death-impacted forests occurred in 2008 in the Big Sur region of California, creating the rare opportunity to study the interaction between an invasive forest pathogen and a historically recurring disturbance. To determine whether and how the sudden oak death pathogen, Phytophthora ramorum, survived the wildfires, we completed intensive vegetation-based surveys in forest plots that were known to be infested before the wildfires. Wethen used 24 plot-based variables as predictors of P. ramorum The likelihood of recovering P. ramorum from burned plots...

Forests are significant stores of carbon (C). This has been recognised by the United Nations Framework Convention on Climate Change and forests are one of the sectors which are included in national greenhouse gas (GHG) inventories. Some of this C pool remains in wood after harvest and can remain in use for long periods of time. Accounting for the C stored in harvested wood products (HWP) can potentially contribute to GHG mitigation. A model was developed for this research to estimate C stocks and flows in HWP in Ireland for the years 1961e2009. The change in carbon stocks in HWP were...

A vegetation-ecologic classification approach has been developed in which a combination of vegetation attributes (physiognomy, structure, and floristics) and their response to ecological and biogeographic factors are used as the basis for classifying vegetation types (Faber-Langendoen et al. 2012). This approach can help support international, national and subnational classification efforts. Support for many aspects of the development of classification was provided by the U.S. National Vegetation Classification (USNVC) partnership, in conjunction with development of the International...

Human populations in the Mid-Atlantic region over the last 250 years have increased nearly 100-fold, from an estimated few hundred thousand people to over 30 million people (Mercer and Murthy 2000). Increased population growth usually results in the conversion of forestland to nonforest uses, particularly agriculture, pastureland, and urban development. Not only is the quantity of forestland reduced, but forest habitat quality also suffers as harvesting and forest conversion patterns chop the forest landscape into smaller, more isolated patches of forest—a process referred to as fragmentation.

Microwave radiation was used as the heating source in southern pine wood liquefaction with PEG/ glycerin binary solvent. It was found that microwave heating was more efficient than conventional oil bath heating for wood liquefaction. The wood residue content of the H2SO4 catalyzed liquefied wood dropped to zero within 5 min with microwave heating. The resulting liquefied wood polyols have suitable hydroxyl values for the preparation of rigid PU foams. Both the compressive strength and apparent modulus of the liquefied-wood-based PU foams increased as the isocyanate index increased from 80...

The recent focus on bioenergy has led to interest in developing alternative technologies for assessing the fuel value of available biomass resources. In this study, both near- and mid-infrared spectroscopic datawere used to predict fuel value in relation to extractives and lignin contents for longleaf pine wood. Samples were analyzed both before and after extraction.Using both near- and mid-infrared spectroscopy, strong correlations were found between fuel value and extractives content for the unextracted wood samples, with the mid-IR models providing better correlations while using less...

The objective of this investigation was to find a simple method for the production of phenolic rich products and sugar derivatives (biopolyols) via separation of liquefied lingocellulosic materials. Liquefaction of lignocellulosic materials was conducted in methanol at 180 °C for 15 min with the conversion of raw materials at about 75%. After liquefaction, the liquefied products were separated by addition of a sufficient amount of water. It was found that the hydrophobic phenolics could be largely separated from aqueous solutions. The phenolic products that precipitated from the aqueous...

Two experiments were performed to determine the physical and mechanical characteristics of panels consisting of a veneer face and a particleboard core composed of mixed wood particles/powdered-recycled polyethylene (PE) bag waste (MWP) using urea-formaldehyde (UF) resin as a binder. The addition of 25 percent powdered-recycled PE bag waste to the MWP panels did not adversely affect nonaged bonding strength but did result in substantial improvement in internal bond (IB) retention after a 24-hour water soak and improved dimensional stability. Average MWP panel IB retention was more than 300...

The chemical compositions of loblolly pine (Pinus taeda L.) bark samples from two industrial sources were determined for whole bark as well as the inner and outer bark components. Differences in extractive contents of the whole bark samples were primarily attributed to the different debarking methods which afforded different proportions of inner and outer bark. Treatment of the extractive-free bark samples with 1 percent NaOH to remove interfering phenolic compounds impacted the lignin contents determined by the Klason method, but not those determined by the acetyl bromide method. Upon...