Treesearch

Lignin is a by-product of biorefineries and pulp and paper manufacturers. Lignin is a renewable source of phenolic precursors for fuels and chemicals. Hydrogenolysis of lignin cleaves the abundant β-O-4 bonds and releases phenolics. However, selective hydrogenolysis of lignin’s β-O-4 bonds is challenging because it requires high-pressure H2. Here we show efficient hydrogenolysis of lignin model compounds and technical lignin by Ru/C catalyst and internal hydrogen. The aliphatic hydroxyl groups (Cα OH) in lignin enabled Ru-catalyzed dehydrogenation of internal hydrogen and the formation of...

Wood-water interactions are central to the utilization of wood in our society since water affects many important characteristics of wood. This topic has been investigated for more than a century, but new knowledge continues to be generated as a result of improved experimental and computational methods. This review summarizes our current understanding of the fundamentals of water in wood and highlights significant knowledge gaps. Thus, the focus is not only on what is currently known but equally important, what is yet unknown. The review covers locations of water in wood; phase changes and...

The United States Capitol building was breached on January 6, 2021. Historically significant materials, many made of wood, were stolen, damaged, or destroyed. Shortly after the breach, the USDA Forest Service, Forest Products Laboratory (FPL) was contacted by the Department of Defense and the Architect of the Capitol and asked to provide technical advice and vintage lumber to aid in restoration efforts. This technical report includes the following: (1) details of FPL efforts to provide vintage lumber specimens to the Architect of the Capitol staff for use in repair of the U.S. Capitol...

Conservation scientists recommend maintaining and restoring ecological connectivity to sustain biodiversity in the face of land-use and climate change. Alternative connectivity assessments conducted at multiple spatial scales are needed to understand consequences of varying assumptions and for use in multi-scale conservation planning.

Wildfire is a natural phenomenon with substantial economic consequences, and its management is complex, dynamic, and rife with incentive problems. This article reviews the contribution of economics to our understanding of wildfire and highlights remaining knowledge gaps. We first summarize economic impacts to illustrate scale and trends. We then focus on wildfire management in three phases: mitigation before fires occur, response during fires, and response after fires. The literature highlights economic interdependencies and spillover effects across fire-prone landscapes as the source of...

The potential for trophic cascades triggered by recent range expansion of the Barred Owl (Strix varia) to the Pacific Northwest has caused concern among conservationists and managers. Barred Owl predation of small forest carnivores is a particular concern because these carnivores typically have low population growth rates relative to their body size owing to long interbirth intervals, which may result in sensitivity to increased mortality. The Western Spotted Skunk (Spilogale gracilis) is a common small carnivore in forests of the Pacific Northwest that may be a prey item for Barred Owls,...

1. Deep soil water utilization allows plants to cope with drought stress. However, little is known about the roles of the understorey layers in driving spatio-temporal variations of deep soil water in forests and how the patterns of deep soil water use among life-forms contribute to community assembly processes.2. We assessed the spatio-temporal patterns and determinants of deep water utilization of tree, shrub and herb layers in subtropical coniferous plantations and investigated associations between deep water use parameters and dominance and richness of understorey vegetation.3. We...

Understanding and predicting the relationship between leaf temperature (Tleaf) and air temperature (Tair) is essential for projecting responses to a warming climate, as studies suggest that many forests are near thermal thresholds for carbon uptake. Based on leaf measurements, the limited leaf homeothermy hypothesis argues that daytime Tleaf is maintained near photosynthetic temperature optima and below damaging temperature thresholds. Specifically, leaves should cool below Tair at higher temperatures (i.e., > ∼25–30°C) leading to slopes <1 in Tleaf /Tair relationships and substantial...

The Swift Terrestrial Passive Acoustic Recording Unit from The Cornell Lab of Ornithology, running firmware v. STM32 0.18.6.3, produced an initial 4-sec sound anomaly in each sound (wave file) recording, created by the power-saving features of the unit as it switches from standby to record mode. The sound anomaly had a statistically significant impact on several soundscape indices calculated from the recordings. Here, as a case study of identifying and solving this problem, I dissected the nature of the anomaly and analyzed the variable effects it has on calculated ecoacoustic soundscape...