Treesearch

The forested watersheds of the Pacific Northwest can sequester a significant amount of atmospheric carbon dioxide (CO2), making them valuable carbon sinks for offsetting the carbon emissions that are contributing to global changes in the climate. However, as trees are storing carbon, water is leaching it from the soil. Some of the carbon is captured by microbial communities living in the stream’s hyporheic zone, a region within the streambed, where it is turned back into CO2. Gas exchanges between water and air release this CO2 back into the atmosphere. These carbon fluxes previously have...

Riparian vegetation along streams provides a suite of ecosystem services in rangelands and thus is the target of restoration when degraded by over-grazing, erosion, incision, or other disturbances. Assessments of restoration effectiveness depend on defensible monitoring data, which can be both expensive and difficult to collect. We present a method and case study to evaluate the effectiveness of restoration of riparian vegetation using a web-based cloud-computing and visualization tool (ClimateEngine.org) to access and process remote sensing and climate data. Restoration efforts on an...

This report highlights significant research findings and accomplishments of the Pacific Northwest Research Station during fiscal year 2017.

We applied a range of bole and root damage treatments to young Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) trees. Significant natural damage occurred to tree crowns over the course of the 10-year study allowing for an analysis of how damage severity to tree boles, tree roots, and tree tops impacts growth and cumulative survival of trees. Tree bole damage severity, measured by percent bole circumference removed, exponentially reduced cumulative survival across the study period, whereas damage to tree roots had no significant impact on survival. Bole damage had different impacts on...

Rarity and life history traits inform multiple dimensions of intrinsic risk to climate and environmental change and can help systematically identify at-risk species. We quantified relative geographic rarity (area of occupancy), climate niche breadth, and life history traits for 114 freshwater fishes, amphibians, and reptiles in the U.S. Pacific Northwest. Our approach leveraged presence-only, publicly available data and traits-based inference to evaluate area of occupancy, climate sensitivity (i.e., climate niche breadth), and a Rarity and Climate Sensitivity (RCS) index of all species...

Wildfires consume existing forest fuels but also leave behind dead shrubs and trees that become fuel to future wildfires. Harvesting firekilled trees is sometimes proposed as an economical approach for reducing future fuels and wildfire severity. Postfire logging, however, is controversial. Some question its fuel reduction benefits and its ecological impacts.David W. Peterson, a research forester with the USDA Forest Service, and his colleagues investigated the long-term effects of postfire logging on woody fuels in 255 coniferous forest stands that burned with high fire severity in 68...

Growing up in a southern Oregon timber town in a family strongly rooted in logging, the U.S. Forest Service (USFS) has always been part of my life. The conflicts which embroiled the USFS during my youth are etched in my memory. I vividly remember when the northern spotted owl Strix occidentalis caurina was listed as federally endangered. Mills closed and parades of coffins rolled down the streets with proclamations that the end of federal timber harvest would spell the end of towns like ours. In college, I learned more about public land management for natural resource sustainability....

Douglas-fir, the most important timber species in the Pacific Northwest, US (PNW), has high stiffness and strength. Growing it in plantations on short rotations since the 1980s has led to concerns about the impact of juvenile/mature wood proportion on wood properties. Lumber recovered from four sites in a thinning trial in the PNW was analyzed for relationships between thinning regime and lumber grade yield. Linear mixed-effects models were developed for understanding how rotation age and thinning affect the lumber grade yield. Log small-end diameter was overall the most important for...

Many rural coastal regions are distinctly vulnerable to sea level rise because of their remoteness, isolation from central planning agencies, and poverty. To better plan for future sea level changes in these regions, an interdisciplinary approach to assess the social and environmental impacts of sea level rise and their dynamic feedbacks is important. In this paper, we use a socio-ecological system framework to investigate sea level rise impacts to the Albemarle-Pamlico Peninsula, a rural, low-lying coastal region in eastern North Carolina. Specifically, we show that 42% of the region...

The Haines Index is used in wildland fire management to evaluate the potential for ‘large and/or erratic’ fire behaviour. Published in 1988 as the Lower Atmospheric Severity Index, it was widely adopted and has become popular among fire managers, especially in the United States. Meteorologists have questioned its validity, however. This study revisits the original publication to consider the scientific basis of the Index. It then examines subsequent studies of the Index’s performance. The original Index formulation is found to be incomplete. Some studies suggest that, nonetheless, there...