10 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
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
Life-Cycle impacts of Inland Northwest and Northeast/North central forest resources
Determining the life-cycle inventory (LCI) and impact of forest harvest, regeneration, and growth is necessary in conducting a life-cycle assessment of wood products. This publication provides quantitative assessments of the economic and environmental impacts of forest management activities covering portions of the Inland Northwest (INW), including Montana, Idaho, and eastern Washington, and of the Northeastern and North Central (NE/NC) forests from Minnesota to Maine and south as far as Missouri, West Virginia, and Pennsylvania. The management scenarios provide the inputs needed to develop an LCI on all the inputs and outputs for wood products as impacted by forest treatments and the harvesting of logs in the region. Productive timberlands were grouped according to forest type, productivity, management intensity, and ownership into three broad forest types in the west: cold, dry, and moist; and four in the east: spruce/fir, northern hardwoods, oak/hickory, and aspen/birch. Spruce/fir represented the feedstock to softwood lumber and a composite of northern hardwoods and oak/hickory the feedstock to hardwood lumber. Simulations used the US Forest Service Forest Vegetation Simulator to estimate standing and harvested biomass and log volumes passed on as resources to the manufacturing segments for lumber, plywood, or oriented strandboard. The combinations of ownership, management intensity, and forest type were stratified and averaged to produce a single estimate of yield and the corresponding harvesting impacts. Both historic harvest rates and increased management intensity scenarios were simulated for each region. In the INW, the shift to the higher intensity scenario increased the average production of merchantable volume at harvest to 249 - 399 m3/ha when averaged across the forested land in each ownership class. For the NE/NC region, the production of merchantable volume averaged 263 m3/ha for softwood and 328 m3/ha for hardwood forests with an insignificant volume response from shifting land into more intensive management. Average growth varied widely for INW forest categories from a low on federal land for the base case of 0.7 - 6.7 m3/haha·yr for moist state and private land under the intensive management alternative. Current condition estimates of softwood log and bark carbon exported for mill processing in the INW and NE/NC regions were 751 and 988 kg/ha·yr, respectively
Integrating Products, Emission Offsets, and Wildfire into Carbon Assessments of Inland Northwest Forests
Forest inventory and harvest data from life-cycle inventory and life-cycle assessment for the forest resources of the Inland Northwest region covering Idaho, Montana, and eastern Washington were used to estimate the impacts of management action on the full suite of carbon accounts that can accrue from forest management. The carbon accounts include the forest, wood products, the benefit gained from using wood products as substitutes for alternative products that are fossil fuel-intensive to produce, and the displacement value of using woody biomass to replace fossil fuel. A landscape-level assessment of projected carbon storage by owner group shows that in 100 yr, management on State and Private Forests can sequester or avoid emissions equal to 294 t/ha of carbon, which equals over 1.9 Gt of carbon across 6.5 Mha. Seventy-nine percent of the carbon accumulates beyond current forest carbon inventories. On National Forests, carbon sequestration and avoided emissions are 152 t/ha over 11 Mha of unreserved forests equaling 1.4 Gt of carbon under predictions for a doubling of the 20th century fire rate. The carbon storage in buildings and the substitution benefits override the potential gains of attempting to leave high carbon stocks stored in the forest in this region where disturbance from fire and insect outbreaks dominates the forest ability to sequester carbon