Treesearch

A novel process is developed for high-volume production of low-cost graphene materials from any solid carbon resources, especially biomass sources. Few-layer graphene materials from solid carbon resources are produced through a molecular cracking and welding (MCW) method. The MCW technique is a single step process with two stages, i.e., graphene-encapsulated core–shell nanoparticles are first formed by catalytic thermal treatment of solid carbon materials. Then in the second stage these core–shell structures are opened by ‘cracking molecules’, and the cracked graphene shells are self-welded...

Low-cost methods to measure forest structure are needed to consistently and repeatedly inventory forest conditions over large areas. In this study we investigate low-cost pushbroom Digital Aerial Photography (DAP) to aid in the estimation of forest volume over large areas in Washington State (USA). We also examine the effects of plot location precision (low versus high) and Digital Terrain Model (DTM) resolution (1 m versus 10 m) on estimation performance. Estimation with DAP and post-stratification with high-precision plot locations and a 1 m DTM was 4 times as efficient (precision per...

Conservation planning for wildlife species requires mapping and assessment of habitat suitability across broad areas, often relying on a diverse suite, or stack, of geospatial data presenting multidimensional controls on a species. Stacks of univariate, independently developed vegetation layers may not represent relationships between each variable that can be characterized by multivariate modeling techniques, leading to inaccurate inferences on the distribution of suitable habitat. In this paper, we examine the role of variable combining in mapping multiple dimensions of greater sage-grouse...

Using a large dataset compiled from studies over the years covering 23 tree species, we developed methods to estimate total and components (stem, bark, branch, and foliage) of aboveground live tree biomass. Missing components in the dataset were imputed using species-specific or generalized (species combined into softwood and hardwood groups) Dirichlet imputation. Geometric means of the imputed stem wood proportions were 8% and 9% higher than the observed geometric mean of stem wood proportions in softwood and hardwood species, respectively. For other components, the differences were...

The mixed severity fire regime of western Oregon forests creates a complex post-fire landscape mosaic with patches of low, moderate and high overstory tree mortality. Conversion of old-growth forests into plantations and post-fire salvage logging are widespread land uses that dramatically affect structure, biomass and carbon stocks. Few studies, however, have quantified the complex responses to wildfire and land management (i.e. logging and post-fire salvage logging) over long time periods. We quantified total aboveground biomass and composition in forest stands following low, moderate,...

Land managers have long recognized the importance of maintaining soil productivity in the context of sustainable forest management. Soil disturbance that results in impaired hydrologic function and changes in certain soil properties (e.g., structure, organic matter) may be detrimental to soil productivity. Little is known about the degree of soil disturbance that results from salvage logging implemented in response to large-scale disturbances in the Southern Region of the Forest Service, U.S. Department of Agriculture. We assess the degree of soil disturbance following harvest operations...

Critical loads of atmospheric deposition help decision-makers identify levels of air pollution harmful to ecosystem components. But when critical loads are exceeded, how can the accompanying ecological risk be quantified? We use a 90% quantile regression to model relationships between nitrogen and sulfur deposition and epiphytic macrolichens, focusing on responses of concern to managers of US forests: Species richness and abundance and diversity of functional groups with integral ecological roles. Analyses utilized national-scale lichen survey data, sensitivity ratings, and modeled...

The chaparral restoration workshop held in Arcadia, CA, in 2013 brought together experts, managers and others to discuss alternatives that more effectively protect, manage and even revegetate diminishing shrublands. This publication is a compilation of some of the workshop and oral presentations that update our current knowledge of shrubland ecology and management with respect to its loss and recovery. Shrubland species have evolved strategies that allow them to endure Mediterranean climate extremes. Combinations of often complex factors allow these plants to survive unpredictable and...

Atmospheric nitrogen and sulfur pollution increased over much of the United States during the twentieth century from fossil fuel combustion and industrial agriculture. Despite recent declines, nitrogen and sulfur deposition continue to affect many plant communities in the United States, although which species are at risk remains uncertain. We used species composition data from >14,000 survey sites across the contiguous United States to evaluate the association between nitrogen and sulfur deposition and the probability of occurrence for 348 herbaceous species. We found that the probability...

A type of blocked experiment has the potential of being poorly designed and analyzed. Several papers by Verrill and co-workers referred to such an experiment as a “predictor sort” experiment. It has also been referred to in other papers and textbooks as “artificial pairing” and “matched pair” or “matched subjects” design. The associated design process is also sometimes described as “forming blocks via a concomitant variable.” In a wood research context, the response in such an experiment might be lumber strength after a treatment, and the predictor used to form blocks would be some...