Treesearch

Throughout Earth’s history, its climates have been changing, and biotic systems have mutated, migrated, and otherwise adapted as tectonic shifts have reconfigured the continents and polar ice caps have ebbed and flowed across the latitudes through glacial cycles. In our own era, there is growing evidence that changes in climate that in the past have taken place over the course of millennia are now taking place in a matter of decades. These accelerated changed in climate are challenge the ability of both human civilization and the natural systems on which it depends, to adapt quickly enough...

The Anthropocene epoch presents a mix of old and new challenges for the world’s forests. Climatic instability has typified most of the Cenozoic Era but today’s situation is unique due to the presence of billions of humans on the planet. The potential rate and magnitude of future warming driven by continued fossil fuel combustion could be unprecedented during the last 56 million years, and the recovery of atmospheric carbon dioxide concentrations to pre-industrial conditions is likely to last tens of thousands of years. Paleoecological records suggest that responses of forests to human-drive...

Forest conservation under climate change requires conserving species both in their present ranges and where they may exist in the future as climate changes. Several debates in the literature are pioneering this relatively novel ground. For instance, conservation planning using species distribution models is advocated because it uses information on both exposure to climate change and species’ sensitivities to climate change, while approaches focusing on land facets are advocated because there is uncertainty regarding both exposure and sensitivity. Other debates include assisted/managed...

What forestry needs in the Anthropogenic Era is what has been needed for the past 30 years. The proper methods, theory, and goals have been clear and are available; the failure has been, and continues to be, that our laws, policies, and actions are misdirected because we confuse a truly scientific base with nonscientific beliefs. The result is a confusion of folklore and science that is counterproductive, both for forests and for human needs and desires. Our love of forests gets confused with our attempts to understand them. In the practical world of incomplete knowledge, our management of...

Mechanical thinning and the application of prescribed fire are commonly used to restore fire-adapted forest ecosystems in the western United States. During a 10-year period, we monitored the effects of fuel-reduction and forest-restoration treatments on levels of tree mortality in an interior ponderosa pine, Pinus ponderosa Dougl. ex Laws., forest in California. Twelve experimental plots, ranging in size from 77-144 ha, were established to create two distinct forest structural types: mid-seral stage (low structural diversity; LoD) and late-seral stage (high structural diversity; HiD)....

Liquefaction of sawdust was studied using glycerol and methanol as mix solvents. A new bio-polyol product consisting of high purity multi-hydroxy compounds was obtained by precipitation of the hydrophobic organics from the liquefied product in an aqueous solution. As identified by GC-MS, the dominate components in bio-polyol were glycerol, glycerol derivatives, and multiple types of sugar derivatives. By using the mass ratio of m (sawdust) : m (glycerol)51 : 1, the total content of multi-hydroxy compounds reached 90.84%. The hydroxyl number of the bio-polyol was 1287 mgKOH/g with a...

Defining functional connectivity between habitats in spatially heterogeneous landscapes is a particular challenge for small-bodied aquatic species. Traditional approaches (e.g. mark-recapture studies) preclude an assessment of animal movement over the life cycle (birth to reproduction), and movement of individuals may not represent the degree of gene movement for fecund species. We investigated the degree of habitat connectivity (defined as the exchange of individuals and genes between mainstem and tributary habitats) in a stream brook trout (Salvelinus fontinalis) population using...

Bamboo residues were subjected to a microwave-assisted liquefaction process for the production of crude bio-polyols (CBP). The fractionated bio-polyols (FBP) were obtained by the removal of lignin derivatives from the crude bio-polyols (CBP) using a simple method. Polyurethane (PU) foams were successfully prepared from both CBP and FBP. The object of this study was to evaluate the effect of lignin derivatives in bio-polyols on the physical properties, thermal stability, and microstructure of PU foams. The results revealed that the PU foam made from CBP had a higher density and superior...

Novel bionanocomposite films have been prepared by depositing xylan onto cellulose nanowhiskers through a pH adjustment. Analysis of strength properties, water vapour transmission, transparency, surface morphology and thermal decomposition showed the enhancement of film performance. This provides a new green route to the utilization of biomass for sustainable biomaterials production.

Four catalysts (H2SO4, HCl, H3PO4, and NaOH/NH4OH) were studied in the preparation of melamine modified urea– formaldehyde (UFM) resins. 13C-nuclear magnetic resonance spectroscopic analysis of the UFM resins at different synthesis stages revealed the polymer structure and detailed reaction mechanism. Three acidic catalysts (H2SO4, HCl, and H3PO4) enhanced the resin polymerization through the formation of various contents of methylene, ether linkages, and urons. H3PO4 yielded the most terminal ether linkages at the first stage and enhanced polycondensation by depleting all free urea and...