Treesearch

The brown-rotted wood was liquefied in phenol with phosphoric acid as catalyst and the resulting liquefied products were condensed with formaldehyde to yield novolak liquefied wood-based phenol formaldehyde resin (LWPF). The results showed that brown-rotted wood could be more easily liquefied than sound wood in phenol. The residue content of liquefied wood decreased continually with the progress of brown-rot decay. Both water wash and neutralization and water wash slightly improved the thermofluidity and curing properties of LWPF with a small reduction of LWPF yield. An increase in phenol...

Crown dieback and mortality of black ash (Fraxinus nigra) has been noted across the range of the species in North America for several decades. Causes of dieback and mortality are not definitive, but may be related to spring drought or excessive moisture. Where black ash is the dominant tree species in the forest, continued dieback and mortality may result in open, non-forest systems in the future. There is only limited research that has examined tree regeneration in black ash-dominated forests and none in stands experiencing dieback and mortality. Such studies are needed to better understan...

An insect's cold hardiness affects its potential to overwinter and outbreak in different geographic regions. In this study, we characterized the response of Helicoverpa zea (Boddie) pupae to low temperatures by using controlled laboratory measurements of supercooling point (SCP), lower lethal temperature (LT50), and lower lethal time (LLTime). The impact of diapause, acclimation, and sex on the cold hardiness of the pupae also were evaluated. Sex did not significantly affect the SCP, LT50, or LLTime. However, the mean SCP of diapausing pupae (-19.3°C) was significantly lower than nondiapaus...

Sustaining Young Forest Communities is a good compilation of knowledge about an important forest ecosystem and belongs on the bookshelf of every natural resource practitioner tasked with managing this important resource. One of the principal benefits for anyone who reads this book is that it provides both a broad overview and a reference source for the various disciplines, particularly for those with which the reader is not familiar, allowing one to gain understanding of the opportunities and issues.

North America has a vast system of hardwood and softwood forests, and the wood harvested from this resource is widely used in many applications. These include lumber and other building materials, furniture, crating, containers, pallets and other consumer goods. This wide array of wood products generates not only a large amount of industrial wood by-product during the manufacturing process, but it also productes a large amount of wood waste when these products are disposed at teh end of their useful lives.

Black ash (Fraxinus nigra) is present throughout the upper Midwest and Northeastern United States and is often found in lowland hardwood forests. Black ash seed is an important food for birds and small mammals, and its twigs and foliage are used by ungulates. Black ash wood is valued for paneling and furniture as well as for Native American basketry. In recent years, the availability of quality trees used to make baskets has diminished because of black ash decline.

Processing of pine wood chips in a pilot-scale downdraft gasifier generated a carbon-rich fly ash as a byproduct. Studies on biomass-derived fly ashes have generally focused on their direct characterisation, as generated, to develop options for utilisation or disposal. Analogous to studies on coal-derived fly ashes, strategies were applied here to assess the feasibility of isolating chars for value-added applications and to determine their elemental compositions relative to that for the feedstock. The inorganic ash content of the biomass-derived fly ash was 48.4%. Sieving followed by...

Changes in land use and land cover have affected and will continue to affect biological diversity worldwide. Yet, understanding the spatially extensive effects of land-cover change has been challenging because data that are consistent over space and time are lacking. We used the U.S. National Land Cover Dataset Land Cover Change Retrofit Product and North American Breeding Bird Survey data to examine landcover change and its associations with diversity of birds with principally terrestrial life cycles (landbirds) in the conterminous United States. We used mixed-effects models and model...

Ecosystems are changing in response to observed changes in climate, extreme events, and disturbances such as fire and insects. We read not only that these changes are occurring but that we should expect them to continue - changes in temperature; more extreme events; and more disturbances such as fire and insects that are not like the past. Key point: these changes in climate and ecosystems are now part of the environment in which resource management occurs.

In its invaded range in western North America, Bromus tectorum (cheatgrass) can host more than 100 sequence-based, operational taxonomic units of endophytic fungi, of which an individual plant hosts a subset. Research suggests that the specific subset is determined by plant genotype, environment, dispersal of locally available endophytes, and mycorrhizal associates. But, interactions among members of the endophyte community could also be important. In a sampling of 63 sites throughout the invaded range of B. tectorum, a fungivorous nematode, Paraphelenchus acontioides, and an endophyte,...