9 research outputs found
Environmental Performance Index for the Forest
Comparative environmental performance indices for energy use, global warming potential (GWP), air, water, and solid waste emissions covering the stages of processing from the harvesting of wood and the extraction of non-renewable materials to the construction of a house using different materials are developed in other articles. Developing performance indices that compare renewable resources and their environmental impacts on the land base to the depletion of non-renewable resources is problematic. Materials that involve mining are inherently not renewable compared to forest resources, which are renewable over some rotation age of the forest. The environmental impacts on the forest are dynamic and are impacted by landscape changes with some related to the production of wood for markets. Forest ecology metrics are developed to show the impact of management alternatives based on changing stand structures. Forest diversity, measured by structure classes, is impacted by longer rotation and thinning alternatives as well as preservation and protection policies.Management alternatives can contribute to some restoration of pre-settlement conditions of forests and provides a benchmark from which to evaluate reduced stand structure diversity and loss of habitat. While a century of commercial management has reduced the diversity in the forest and in particular has increased the share of acres in both the stand initiation stage and the closed canopy or stem exclusion stage, the trend has already turned in response to demands for more forest acres under increased protection and preservation status. Increased thinning from more intensive management and policies to protect threatened species are both contributing to increased understory reinitiation and ultimately more complex old forest structures. Longer rotation management could add to this effect but at a substantial cost since the economics of long rotation management falls below acceptable levels for economic investments
An Assessment of Carbon Pools, Storage, and Wood Products Market Substitution Using Life-Cycle Analysis Results
The study utilized the results from a life-cycle assessment (LCA) of housing construction to analyze forest products' role in energy displacement and carbon cycling. It analyzed the behavior of three carbon pools associated with forest products: the forest, forest products, and fossil fuel displaced by forest products in end-use markets. The LCA provided data that allowed us to create an accounting system that tracked carbon from sequestration to substitution in forest product end-use markets. The accounts are time-dependent since the size of the carbon pools is influenced by harvest timing; hence the size of each pool is estimated under alternative harvesting scenarios and presented over time. The analysis of the alternative harvesting scenarios resulted in shorter harvest cycles and provided the largest carbon pools when all three pools were considered together. The study concluded that forest products led to a significant reduction in atmospheric carbon by displacing more fossil fuel-intensive products in housing construction. The result has important policy implications since any incentive to manage forest lands to produce a greater amount of forest products would likely increase the share of lands positively contributing to a reduction of carbon dioxide in the atmosphere
Life-Cycle Impacts of Forest Resource Activities in the Pacific Northwest and Southeast United States
A more intensive management alternative was created for each region by reallocating acres to higher management intensity classes. Harvesting activities were segmented into five stages to allow development of all inputs and outputs: (1) felling, (2) processing (bucking, limbing, cutting to length), (3) secondary transportation (skidding and yarding), (4) loading, and (5) hauling to a process point. The costs and consumption rates of energy and materials for these activities drove the log outputs, emissions, and carbon pools. Logs are allocated to wood product facilities, the primary product of the analysis, or pulp and paper mills as a co-product from the forest. Non-merchantable slash is generally left on site and is disposed of through site preparation activities. Transportation-related activities and the required diesel fuel produce by far the largest contribution to emission outputs. However, fertilizer use contributes to much of the change in emissions as acreage shifts to higher intensity management alternatives
Genome-Wide Scan for Parent-of-Origin Effects in a sub-Saharan African Cohort With Nonsyndromic Cleft Lip and/or Cleft Palate (CL/P)
A Social Media Intervention for Promoting Oral Health Behaviors in Adolescents: A Non-Randomized Pilot Clinical Trial
Poor oral hygiene and excessive consumption of soda are among the main drivers of systemic health issues in adolescents in the United States. This non-randomized pilot clinical trial focused on the effects of a health text message system and smartphone-based intervention on adolescent tooth-brushing behavior and dietary choices, with a convenience sample of 94 participants aged 12 to 14 years old. A group of 75 participants agreed to use a tooth-brushing app and received a health text message; the other group of 15 agreed to use the tooth-brushing app, but did not receive a health text message. Saliva specimens were collected directly before and at the end of each experiment; changes in the salivary presence of cariogenic bacteria over the duration of the study were evaluated and compared with the demographics and behavioral variables. Within the text message group, 5% of participants increased the frequency of daily tooth brushing. Within the non-intervention group, 29% of participants increased the frequency of their daily tooth brushing. There were reductions in the total salivary bacteria and total streptococci in both groups (p Mutans streptococci. Raising adolescents’ consciousness of oral health behavior resulted in marginal to moderate improvements to oral hygiene and dietary choices, as well as reductions in total salivary bacteria
Climate and air pollution impacts of generating biopower from forest management residues in California
California faces crisis conditions on its forested landscapes. A century of aggressive logging and fire suppression in combination with conditions exacerbated by climate change have created an ongoing ecological, economic, and public health emergency. Between commercial harvests on California’s working forestlands and the increasing number of acres the state treats each year for fire risk reduction and carbon sequestration, California forests generate millions of tons of woody residues annually—residues that are typically left or burned in the field. State policymakers have turned to biomass electricity generation as a key market for woody biomass in the hope that it can support sustainable forest management activities while also providing low-carbon renewable electricity. However, open questions surrounding the climate and air pollution performance of electricity generation from woody biomass have made it difficult to determine how best to manage the risks and opportunities posed by forest residues. The California Biomass Residue Emissions Characterization (C-BREC) model offers a spatially-explicit life cycle assessment framework to rigorously and transparently establish the climate and air pollution impacts of biopower from forest residues in California under current conditions. The C-BREC model characterizes the variable emissions from different biomass supply chains as well as the counterfactual emissions from prescribed burn, wildfire, and decay avoided by residue mobilization. We find that the life cycle ‘carbon footprint’ of biopower from woody residues generated by recent forest treatments in California ranges widely—from comparable with solar photovoltaic on the low end to comparable with natural gas on the high end. This variation stems largely from the heterogeneity in the fire and decay conditions these residues would encounter if left in the field, with utilization of residue that would otherwise have been burned in place offering the best climate and air quality performance. California’s energy and forest management policies should account for this variation to ensure desired climate benefits are achieved