Treesearch

Aim: Anticipating when and where changes in species' demographic rates will lead to range shifts in response to changing climate remains a major challenge. Despite evidence of increasing mortality in dry forests across the globe in response to drought and warming temperatures, the overall impacts on the distribution of dry forests are largely unknown because we lack comparable large-scale data on tree recruitment rates. Here, our aim was to develop range-wide population models for dry forest tree species (pinyon pine and juniper), quantifying both mortality and recruitment, to better...

Crops emit a variety of volatile organic compounds (VOCs) that serve as attractants or repellents for pests and their natural enemies. Crop rotations, off-farm chemical inputs, and mechanical and cultural tactics - collectively called cropping systems – alter soil nutrients, moisture content, and microbial communities, all of which have the potential to alter crop VOC emissions. Soil legacy effects of diversified cropping systems have been shown to enhance crop VOC emissions in greenhouse studies, but how they influence emissions under field conditions remains virtually unknown. To...

We demonstrate the potential for pushbroom Digital Aerial Photogrammetry (DAP) to enhance forest modeling (and mapping) over large areas, especially when combined with multitemporal Landsat derivatives. As part of the National Agricultural Imagery Program (NAIP), high resolution (30–60 cm) photogrammetric forest structure measurements can be acquired at low cost (as low as $0.23/km2 when acquired for entire states), repeatedly (2–3 years), over the entire conterminous USA. Our three objectives for this study are to: (1) characterize agreement between DAP measurements with Landsat and...

Climate change is contributing to biodiversity redistributions and species declines. However, cooler microclimate conditions provided by old-growth forest structures compared with surrounding open or younger forests have been hypothesized to provide thermal refugia for species that are sensitive to climate warming and dampen the negative effects of warming on population trends of animals (i.e., the microclimate buffering hypothesis). In addition to thermal refugia, the compositional and structural diversity of old-growth forest vegetation itself may provide resources to species that are...

Sustainable aviation fuel (SAF) is vital for the reduction of the environmental impact of the aviation industry while decreasing the dependence of the USA on foreign petroleum fuels. To date, SAF, especially from cellulosic feedstocks, have struggled to overcome two barriers: (1) meeting price parity with their petroleum counterparts and (2) the large capital investment required for industrial-scale biorefineries. Repurposing of industrial facilities has been suggested as a means of addressing both challenges. In this study we look at the financial impact of manufacturing SAF using three...

The aim of this study was to evaluate the efficacy of biological and chemical remediation of chromated copper arsenate (CCA) treated Corymbia citriodora poles, removed from service after 30 years. The presence of arsenic (As), chromium (Cr) and copper (Cu) was quantified by inductively coupled plasma optical emission spectrometry (ICP–OES). Twelve species of decay fungi were used for the biological remediation assay. For chemical remediation oxalic, citric, maleic and ethylenediamine tetraacetic (EDTA) acids were used for 24 and 48 h. In biological remediation, copper-tolerant brown-rot...

Due to the large amount of inherent chemical energy, implementation of hydrogen peroxide pulp bleaching requires a high level of safety design and process review. Even with safety controls, in-place accidents have occurred at kraft pulp bleaching facilities. Using a combination of experiments and chemical engineering analysis, we present a validated model of hydrogen peroxide decomposition under alkaline conditions that are typically found in kraft pulp bleaching processes. Using the model, we then calculated several characteristic parameters required to determine the criticality class and...

A fundamental question of forestry is that of species composition: which species are present, and which are not. However, traditional forest measurements needed to map species over large areas can be both time consuming and costly. In this study, we combined airborne light detection and ranging (LiDAR) data with extensive field data from the Long-Term Ecosystem Productivity study located near Sappho,Washington, USA to increase the accuracy of our GIS data and to differentiate between red alder (Alnus rubra Bong.) and other dominant tree species. We adjusted plot and tree locations using...

There is considerable interest in multiaged management as a silvicultural and restoration tool in redwood forests of California. For multiaged silviculture to be successful, a new cohort of trees must first be able to regenerate underneath the residual overstory. We used annual re-measurement data from a replicated manipulative experiment in coastal northern California to determine how understory light, stand density, and spatial arrangement of residual trees affected coast redwood (Sequoia sempervirens) and tanoak (Notholithocarpus densiflorus) stump sprouts regenerating after partial...

Using woody biomass from public lands could attract private investments, increase carbon dioxide emission reductions from sustainably harvested low‐grade wood to mitigate climate change, provide benefits for the environment, and support rural community economies. Available for use are about 210 million oven dry tons (in the western U.S. alone) of small‐diameter wood and harvest residues that could be removed through hazard‐fuel treatments and used for bioenergy and bioproducts; representing an economic value of approximately USD 5.97 billion (109). Reaching that utilization goal requires...