Treesearch

Alaska’s Arctic tundra is one of the most rapidly warming regions in the world. For years, scientists have been working to interpret the effects of its changing climate and determine what these changes may mean for the rest of the planet. Coarse-scale satellite imagery of much of this region shows the tundra is becoming greener. This has been widely attributed to shrub expansion. To better understand vegetation dynamics in the region, research ecologist Robert Pattison and his colleagues compared satellite imagery of this greening with data that Janet Jorgenson, a botanist with the U.S....

The Community Biomass Handbook Volume 4: Enterprise Development for Integrated Wood Manufacturing is a guide for creating sustainable business enterprises using small diameter logs and biomass. This fourth volume is a companion to three Community Biomass Handbook volumes: Volume 1: Thermal Wood Energy; Volume 2: Alaska, Where Woody Biomass Can Work; and Volume 3: How Wood Energy is Revitalizing Rural Alaska. This volume is designed to help business partnerships, forest managers, and community groups rapidly explore and evaluate integrated manufacturing opportunities. The handbook is...

As a signatory to the United Nations Framework Convention on Climate Change, the United States annually compiles a report on the nation’s carbon flux—the amount of carbon emitted into the atmosphere compared to the amount stored by terrestrial landscapes. Forests store vast amounts of carbon, but it’s not fully understood how a forest’s storage capacity fluctuates as stands age or respond to disturbance. To calculate the carbon flux in the forests of Oregon and Washington, scientists with the U.S. Forest Service Pacific Northwest Research Station compiled field measurements and quantified...

The Blue Mountains Adaptation Partnership was developed to identify climate change issues relevant to resource management in the Blue Mountains region, to find solutions that can minimize negative effects of climate change, and to facilitate transition of diverse ecosystems to a warmer climate. Partnering organizations included three national forests (Malheur, Umatilla, Wallowa-Whitman National Forests), the Pacific Northwest Research Station and Pacific Northwest Region of the U.S. Department of Agriculture, Forest Service, the University of Washington, and the Climate Impacts Research...

Wild and prescribed fire-induced injury to forest trees can produce immediate or delayed tree mortality but fire-injured trees can also survive. Land managers use logistic regression models that incorporate tree-injury variables to discriminate between fatally injured trees and those that will survive. We used data from 4024 ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and 3804 Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees from 23 fires across Oregon and Washington to assess the discriminatory ability of 21 existing logistic regression models and a polychotomous key (Scott...

Wildfire area is predicted to increase with global warming. Empirical statistical models and process-based simulations agree almost universally. The key relationship for this unanimity, observed at multiple spatial and temporal scales, is between drought and fire. Predictive models often focus on ecosystems in which this relationship appears to be particularly strong, such as mesic and arid forests and shrublands with substantial biomass such as chaparral. We examine the drought–fire relationship, specifically the correlations between water-balance deficit and annual area burned, across...

The ecological outcomes of civic environmental stewardship are poorly understood, especially at scales larger than individual sites. In this study we characterized civic environmental stewardship programs in the Green-Duwamish watershed in King County, WA, and evaluated the extent to which stewardship outcomes were monitored. We developed a four-step process based on the Open Standards for the Practice of Conservation to structure our evaluation and to make recommendations for future monitoring of ecological outcomes of stewardship activities. Environmental stewardship, primarily in the...

Societies use biologically active chemicals as medicines and pesticides to protect human and agricultural health. But widespread use of synthetic compounds raises concerns about their safety, and resistance development in targeted pests. To find safer alternatives, scientists turned to native plants and trees in Pacific Northwest forests using multiyear exploratory surveys. Researchers collected samples from different plant and tree parts for extraction and toxicity testing with a simple brine shrimp bioassay. These bioassays detected strong biological activity in heartwood extracts from...

Hand-constructed piles in eastern Washington and north-central New Mexico were weighed periodically between October 2011 and June 2015 to develop decay-rate constants that are useful for estimating the rate of piled biomass loss over time. Decay-rate constants (k) were determined by fitting negative exponential curves to time series of pile weight for each site. Piles at the Washington site (k = 0.027/year) decomposed significantly more slowly than piles at the New Mexico site (k = 0.064/year). Significant differences in k for each site may be a function of a between-site variation in pile...

Context Conservation planning for at-risk species requires understanding of where species are likely to occur, how many individuals are likely to be supported on a given landscape, and the ability to monitor those changes through time. Objectives We developed a distribution model for northern spotted owls that incorporates both habitat suitability and probability of territory occupancy while accounting for interspecies competition. Methods We developed range-wide habitat suitability maps for two time periods (1993 and 2012) for northern spotted owls that accounted for regional differences...