http://www.fs.fed.us/pnw/publications/ecosystemservices.shtml Pacific Northwest Research Station - Ecosystem Services Publications en-us http://www.fs.fed.us/pnw/pubs/pnw_gtr879.pdf Indigenous populations are projected to face disproportionate impacts as a result of climate change in comparison to nonindigenous populations. For this reason, many American Indian and Alaska Native tribes are identifying and implementing culturally appropriate strategies to assess climate impacts and adapt to projected changes. Traditional ecological knowledge (TEK), as the indigenous knowledge system is called, has the potential to play a central role in both indigenous and nonindigenous climate change initiatives. The detection of environmental changes, the development of strategies to adapt to these changes, and the implementation of sustainable land-management principles are all important climate action items that can be informed by TEK. Although there is a significant body of literature on traditional knowledge, this synthesis examines literature that specifically explores the relationship between TEK and climate change. The synthesis describes the potential role of TEK in climate change assessment and adaptation efforts. It also identifies some of the challenges and benefits associated with merging TEK with Western science, and reviews the way in which federal policies and administrative practices facilitate or challenge the incorporation of TEK in climate change initiatives. The synthesis highlights examples of how tribes and others are including TEK into climate research, education, and resource planning and explores strategies to incorporate TEK into climate change policy, assessments, and adaptation efforts at national, regional, and local levels.​ Vinyeta, Kirsten; Lynn, Kathy Fri., 17 May 2013 11:00:00 PST Gen. Tech. Rep. PNW:GTR:879. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 37 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr862.pdf Forest managers are seeking practical guidance on how to adapt their current practices and, if necessary, their management goals, in response to climate change. Science-management collaboration was initiated on national forests in eastern Washington where resource managers showed a keen interest in science-based options for adapting to climate change at a 2-day workshop. Scientists and managers reviewed current climate change science and identified resources vulnerable to expected climate change. Vulnerabilities related to vegetation and habitat management included potential reductions in forest biodiversity and low forest resilience to changing disturbance regimes. The vulnerabilities related to aquatic and infrastructure resources included changing water quality and quantity, the risk to roads and other facilities from changes to hydrologic regimes, and the potential loss of at-risk aquatic species and habitats. Managers then worked in facilitated groups to identify adaptations that could be implemented through management and planning to reduce the vulnerability of key resources to climate change. The identified adaptations were grouped under two major headings: Increasing Ecological Resiliency to Climate Change, and Increasing Social and Economic Resiliency to Climate Change. The information generated from the science-management collaborative represents an initial and important step in identifying and prioritizing tangible steps to address climate change in forest management. Next would be the development of detailed implementation strategies that address the identified management adaptations.. Gaines, William L.; Peterson, David W.; Thomas, Cameron A.; Harrod, Richy J. Mon., 15 Oct 2012 13:50:00 PST Gen. Tech. Rep. PNW-GTR-862. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 34 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr867.pdf Cofiring of biomass and coal at electrical generation facilities is gaining in importance as a means of reducing fossil fuel consumption, and more than 40 facilities in the United States have conducted test burns. Given the large size of many coal plants, cofiring at even low rates has the potential to utilize relatively large volumes of biomass. This could have important forest management implications if harvest residues or salvage timber are supplied to coal plants. Other feedstocks suitable for cofiring include wood products manufacturing residues, woody municipal wastes, agricultural residues, short-rotation intensive culture forests, or hazard fuel removals. Cofiring at low rates can often be done with minimal changes to plant handling and processing equipment, requiring little capital investment. Cofiring at higher rates can involve repowering entire burners to burn biomass in place of coal, or in some cases, repowering entire powerplants. Our research evaluates the current status of biomass cofiring in North America, identifying current trends and success stories, types of biomass used, coal plant sizes, and primary cofiring regions. We also identify potential barriers to cofiring. Results are presented for more than a dozen plants that are currently cofiring or have recently announced plans to cofire. Nicholls, David; Zerbe, John Fri., 31 Aug 2012 8:55:00 PST Gen. Tech. Rep. PNW-GTR-867. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 22 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr865.pdf The U.S. Forest Service has adopted the concept and language of ecosystem services to describe the beneficial outcomes of national forest management. We review the economic theory of ecosystem services as it applies to public lands management, and consider what it implies about the types of biophysical and other data that are needed for characterizing management outcomes as changes in ecosystem services. Our intent is to provide a guide to policymakers, managers, researchers, and others for evaluating and describing the tradeoffs involved in the management of public lands. Characterizing ecosystem services fundamentally is about explaining the benefits of national forests to the American public, with an emphasis on addressing their interests and concerns about how public lands are managed. Our hope is that this report will foster dialog about what people value about national forests and how public land management agencies might best go about securing those benefits. Kline, Jeffrey D.; Mazzotta, Marisa J. Tue, 26 Jun 2012 10:37:00 PST Gen. Tech. Rep. PNW-GTR-865. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 48 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_rp588.pdf Concerns about forest health and the threat of wildfire across the Western United States increasingly provide the impetus for communities to find land management solutions that serve multiple interests. Funding and procedural changes over the past decade have positioned federal agencies to put greater emphasis on multistakeholder partnerships and public outreach efforts. Partnerships build slowly over time, but can result in a healthier resource, reduced fire risk, greater stability for agency planning processes, and more resilient communities. Drawing on interviews with stakeholders representing broad interests in a partnership between the Northeast Washington Forestry Coalition and the Colville National Forest, we examine some of the critical factors leading to the partnership's success and identify challenges along the way. We illustrate how the citizens of Colville, Washington, overcame conflicts by learning to communicate their interests and use existing resources to advance a variety of goals, ranging from fuels reduction and active forest management to roadless area and wilderness management. We highlight a set of important organizational themes that have emerged from Colville to provide managers and other stakeholders with ideas for similar efforts. Gordon, Ryan; Mallon, Angela; Maier, Carolin; Kruger, Linda; Shindler, Bruce Thu, 31 May 2012 14:55:00 PST Res. Pap. PNW-RP-588. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 15 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr860.pdf Principal findings of the National Fire and Fire Surrogate (FFS) study are presented in an annotated bibliography and summarized in tabular form by site, discipline (ecosystem component), treatment type, and major theme. Composed of 12 sites, the FFS is a comprehensive multidisciplinary experiment designed to evaluate the costs and ecological consequences of alternative fuel reduction treatments in seasonally dry forests of the United States. The FFS has a common experimental design across the 12-site network, with each site a fully replicated experiment that compares four treatments: prescribed fi re, mechanical treatments, mechanical + prescribed fire, and an unmanipulated control. We measured treatment cost and variables within several components of the ecosystem, including vegetation, the fuel bed, soils, bark beetles, tree diseases, and wildlife in the same 10-ha experimental units. This design allowed us to assemble a fairly comprehensive picture of ecosystem response to treatment at the site scale, and to compare treatment response across a wide variety of conditions. McIver, James; Erickson, Karen; Youngblood, Andrew Wed., 04 Apr 2012 12:40:00 PST Gen. Tech. Rep. PNW-GTR-860. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 210 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr856.pdf We used two data sets to evaluate stream and watershed condition for sixth-field watersheds in each aquatic province within the Northwest Forest Plan (NWFP) area: stream data and upslope data. The stream evaluation was based on inchannel data (e.g., substrate, pieces of large wood, water temperature, pool frequency, and macroinvertebrates) we sampled from 2002 to 2009 (193 watersheds) as part of a repeating sample design. We just completed our first round of sampling, so only current condition was calculated for this data set. When condition scores for the inchannel data were grouped into categories, relatively few fell into the low (10 percent) and very low (1 percent) categories. The majority of inchannel attribute scores fell into the moderate (35 percent) and high (41 percent) condition ranges, with relatively few (12 percent) in the very high category. For low-scoring watersheds, water temperature was often the most influential factor. Aquatic invertebrate scores also appeared influential in producing the low scores. Lanigan, Steven H.; Gordon, Sean N.; Eldred, Peter; Isley, Mark; Wilcox, Steve; Moyer, Chris; Andersen, Heidi Fri 24 Feb 2012 10:35 PDT Gen. Tech. Rep. PNW-GTR-856. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 155 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr849.pdf The past decade has seen resurgence in interest in gathering wild plants and fungi in cities. In addition to gathering by individuals, dozens of groups have emerged in U.S., Canadian, and European cities to facilitate access to nontimber forest products (NTFPs), particularly fruits and nuts, in public and private spaces. Recent efforts within cities to encourage public orchards and food forests, and to incorporate more fruit and nut trees into street tree planting programs indicate a growing recognition among planners that gathering is an important urban activity. McLain, R.J.; MacFarland, K.; Brody, L.; Hebert, J.; Hurley, P.; Poe, M.; Buttolph, L.P.; Gabriel, N.; Dzuna, M.; Emery, M.R.; Charnley, S Thu, 23 Feb 2012 14:00:00 PST Gen. Tech. Rep. PNW-GTR-849. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 107 p Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr855.pdf This guidebook contains science-based principles, processes, and tools necessary to assist with developing adaptation options for national forest lands. The adaptation process is based on partnerships between local resource managers and scientists who work collaboratively to understand potential climate change effects, identify important resource issues, and develop management options that can capitalize on new opportunities and reduce deleterious effects. Because management objectives and sensitivity of resources to climate change differ among national forests, appropriate processes and tools for developing adaptation options may also differ. Peterson, David L.; Millar, Connie I.; Joyce, Linda A.; Furniss, Michael J.; Halofsky, Jessica E.; Neilson, Ronald P.; Morelli, Toni Lyn Wed, 18 Jan 2012 10:00:00 PST Gen. Tech. Rep. PNW-GTR-855. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 109 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr850.pdf This is the second in a series of periodic monitoring reports on northern spotted owl (Strix occidentalis caurina) population and habitat trends on federally administered lands since implementation of the Northwest Forest Plan in 1994. Here we summarize results from a population analysis that included data from longterm demographic studies during 1985–2008. This data was analyzed separately by study area, and also in a meta-analysis across all study areas to assess temporal and spatial patterns in fecundity, apparent survival, recruitment, and annual rates of population change. Davis, Raymond J.; Dugger, Katie M.; Mohoric, Shawne; Evers, Louisa; Aney, William C. Fri 04 Nov 2011 10:02 PDT Gen. Tech. Rep. PNWGTR-850. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 147 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_rb263.pdf The Forest Inventory and Analysis program collected, analyzed, and summarized field data on 44 forested field plots for the 10 largest atoll groups in the Republic of the Marshall Islands (RMI): Ailinglaplap, Arno, Jaluit, Kwajalein, Likiep, Majuro, Maloelap, Mili, Rongelap, and Wotje. Donnegan, Joseph A.; Butler, Sarah L.; Kuegler, Olaf; Hiserote, Bruce A. Wed 26 Oct 2011 08:18:00 PDT Resour. Bull. PNW-RB-263. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 161 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_rb262.pdf The Forest Inventory and Analysis program collected, analyzed, and summarized field data on 73 forested field plots on the islands of Kosrae, Chuuk, Pohnpei, and Yap in the Federated States of Micronesia (FSM). Donnegan, Joseph A.; Butler, Sarah L.; Kuegler, Olaf; Hiserote, Bruce A. Wed 26 Oct 2011 08:15:00 PDT Resour. Bull. PNW-RB-262. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 161 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_rb261.pdf The Forest Inventory and Analysis program collected, analyzed, and summarized field data on 37 field plots on the islands of Rota, Tinian, and Saipan in the Commonwealth of the Northern Mariana Islands (CNMI). Donnegan, Joseph A.; Butler, Sarah L.; Kuegler, Olaf; Hiserote, Bruce A. Wed 26 Oct 2011 08:00:00 PDT Resour. Bull. PNW-RB-261. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 161 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr848.pdf The primary objectives of the effectiveness monitoring plan for the marbled murrelet (Brachyramphus marmoratus) include mapping baseline nesting habitat (at the start of the Northwest Forest Plan [the Plan]) and estimating changes in that habitat over time. Using vegetation data derived from satellite imagery, we modeled habitat suitability by using a maximum entropy model. We used Maxent software to compute habitat suitability scores from vegetation and physiographic attributes based on comparisons of conditions at 342 sites that were occupied by marbled murrelets (equal numbers of confirmed nest sites and likely nest sites) and average conditions over all forested lands in which the murrelets occurred. We estimated 3.8 million acres of higher suitability nesting habitat over all lands in the murrelet's range in Washington, Oregon, and California at the start of the Plan (1994/96). Most (89 percent) baseline habitat on federally administered lands occurred within reserved-land allocations. A substantial amount (36 percent) of baseline habitat occurred on nonfederal lands. Over all lands, we observed a net loss of about 7 percent of higher suitability potential nesting habitat from the baseline period to 2006/07. If we focus on losses and ignore gains, we estimate a loss of about 13 percent of the higher suitability habitat present at baseline, over this same period. Fire has been the major cause of loss of nesting habitat on federal lands since the Plan was implemented; timber harvest is the primary cause of loss on nonfederal lands. We also found that murrelet population size is strongly and positively correlated with amount of nesting habitat, suggesting that conservation of remaining nesting habitat and restoration of currently unsuitable habitat is key to murrelet recovery. Raphael, Martin G.; Falxa, Gary A.; Dugger, Katie M.; Galleher, Beth M.; Lynch, Deanna; Miller, Sherri L.; Nelson, S. Kim; Young, Richard D. Mon, 29 Aug 2011 13:39:00 PST Gen. Tech. Rep. PNW-GTR-848. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 52 p Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr839.pdf Traditionally, there has been a strong forest products trade between Alaska and Asia. This trade relationship has developed owing to Alaska's proximity to Asia and, in the past, an abundance of high-quality timber. Although forest products markets in North America remain soft, markets in Asia are growing. However, to benefit from Asia's growing forest products market, it is important to understand the concepts of global shipping including containerization, intermodal transport, non vessel operating common carriers, and freight forwarders. One key development that could have a major impact on Alaska's forest products trade is the opening of the Port of Prince Rupert (British Columbia) in 2007. The Port of Prince Rupert ships lumber, logs, and wood pellets to Asia and is much closer to southeast Alaska than are the ports of Seattle and Tacoma. The Prince Rupert port is also 1 day closer to Asia. Despite Prince Rupert's proximity to Alaska, however, there is still no regularly scheduled barge service between the Port of Prince Rupert and southeast Alaska. Potential connections that may develop are examined in this paper. This paper also examines the changing concepts of global shipping and how they affect Alaska's forest products industry. Roos, Joseph A.; Brackley, Allen M.; Sasatani, Daisuke. Mon 29 Aug 2011 1350:00 PST Gen. Tech. Rep. PNW-GTR-839. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 30p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr838.pdf The effects of climate change are expected to be more severe for some segments of society than others because of geographic location, the degree of association with climate-sensitive environments, and unique cultural, economic, or political characteristics of particular landscapes and human populations. Social vulnerability and equity in the context of climate change are important because some populations may have less capacity to prepare for, respond to, and recover from climate-related hazards and effects. Such populations may be disproportionately affected by climate change. This synthesis of literature illustrates information about the socioeconomic, political, health, and cultural effects of climate change on socially vulnerable populations in the United States, with some additional examples in Canada. Through this synthesis, social vulnerability, equity, and climate justice are defined and described, and key issues, themes, and considerations that pertain to the effects of climate change on socially vulnerable populations are identified. The synthesis reviews what available science says about social vulnerability and climate change, and documents the emergence of issues not currently addressed in academic literature. In so doing, the synthesis identifies knowledge gaps and questions for future research. Lynn, Kathy; MacKendrick, Katharine; and Donoghue, Ellen M. Wed 03 Aug 2011 10:20:00 PST Gen. Tech. Rep. PNW-GTR-838. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 70p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr851.pdf The United States, in partnership with 11 other countries, participates in the Montreal Process. Each country assesses national progress toward the sustainable management of forest resources by using a set of criteria and indicators agreed on by all member countries. Several indicators focus on nontimber forest products (NTFPs). In the United States, permit and contract data from the U.S. Forest Service and the Bureau of Land Management, in addition to several other data sources, were used as a benchmark to assess harvest, value, employment, exports and imports, per capita consumption, and subsistence uses for many NTFPs. The retail value of commercial harvests of NTFPs from U.S. forest lands is estimated at $1.4 billion annually. Nontimber forest products in the United States are important to many people throughout the country for personal, cultural, and commercial uses, providing food security, beauty, connection to culture and tradition, and income. Alexander, Susan J.; Oswalt, Sonja N.; Emery, Marla R. Wed, 20 Jul 2011 11:10:00 PST Gen. Tech. Rep. PNW-GTR-851. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 36 p Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr818.pdf Lichens are one of several forest health indicators sampled every year for a subset of plots on the permanent grid established by the Forest Inventory and Analysis (FIA) Program of the U.S. Department of Agriculture Forest Service. This report reviews analysis procedures for standard FIA lichen indicator data. Analyses of lichen data contribute to state, regional, and national reports that evaluate spatial pattern and temporal trends in forest biodiversity, air quality, and climate. Will-Wolf, Susan Tue, 12 Oct 2010 14:50:00 PST Gen. Tech. Rep. PNW-GTR-818. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 62 p. Douglas Beebe http://www.fs.fed.us/pnw/pubs/pnw_gtr807.pdf Development of a regional lichen gradient model from community data is a powerful tool to derive lichen indexes of response to environmental factors for large-scale and long-term monitoring of forest ecosystems. The Forest Inventory and Analysis (FIA) Program of the U.S. Department of Agriculture Forest Service includes lichens in its national inventory of forests of the United States, to help monitor the status of forested ecosystems. Will-Wolf, Susan; Neitlich, Peter Tue, 12 Oct 2010 14:50:00 PST Gen. Tech. Rep. PNW-GTR-807. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 65 p. Douglas Beebe http://www.fs.fed.us/pnw/sciencef/scifi116.pdf Forests significantly influence the global carbon budget: they store massive amounts of carbon in their wood and soil, they sequester atmospheric carbon as they grow, and they emit carbon as a greenhouse gas when harvested or converted to another use. Thompson, Jonathan Thur, 3 Sep 2009 08:20:00 PST Science Findings 116. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 5 p. Tiffany Dong http://www.fs.fed.us/pnw/sciencef/scifi115.pdf Excess nitrogen stemming from human activities is a common water pollutant. Fertilizer runoff, sewage, and fossil fuel emission all contain nitrogen that often ends in streams, rivers, and ultimately the ocean. Mazza, Rhonda. Tue, 11 Aug 2009 11:20:00 PST Science Findings 115. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 5 p. Tiffany Dong http://www.fs.fed.us/pnw/pubs/pnw_gtr750.pdf Estimates of forest carbon stores and flux for California circa 1990 were modeled from forest inventory data in support of California's legislatively mandated greenhouse gas inventory. Reliable estimates of live-tree carbon stores and flux on timberlands outside of national forest could be calculated from periodic inventory data collected in the 1980s and 1990s; however, estimation of circa 1990 flux on national forests and forests other than timberland was problematic owing to a combination of changing inventory protocols and definitions and the lack of remeasurement data on those land categories. We estimate annual carbon flux on the 7.97 million acres of timberlands outside of national forests (which account for 24 percent of California's forest area and 28 percent of its live tree aboveground biomass) at 2.9 terragrams per year. Fried, Jeremy S.; Zhou, Xiaoping Mon, 21 Apr 2008 11:20:00 PST Gen. Tech. Rep. PNW-GTR-750. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 25 p. Tiffany Dong http://www.fs.fed.us/pnw/publications/pnw_gtr733/ A primary mission of the U.S. Department of Agriculture Forest Service is multiple resource management, and one of the emerging themes is forest restoration. The National Silviculture Workshop, a biennial event co-sponsored by the Forest Service, was held May 7-10, 2007, in Ketchikan, Alaska, with the theme of "Integrated Restoration of Forested Ecosystems to Achieve Multiresource Benefits." This proceedings presents a compilation of state-of-the-art silvicultural research and forestry management papers that demonstrates integrated restoration to yield multiple resource benefits. These papers highlight national perspectives on ecosystem services, forest restoration and climate change, and regional perspectives on forest restoration and silvicultural practices to achieve multiple resource benefits from researchers and forest practitioners working in a broad array of forest types in the United States. Deal, Robert L., tech. ed. Tue, 27 Feb 2008 08:40:00 PST Gen. Tech. Rep. PNW-GTR-733. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 306 p. Tiffany Dong http://www.fs.fed.us/pnw/pubs/pnw_gtr729.pdf The demand for water is rapidly increasing, but the uses to which that water is put and the values society places on water are changing dramatically. Water is the source of life, the sustenance for living, the resource needed for manufacturing, mining, agriculture; the element required to grow our lawns, to water our landscaping, to shower us with refreshment; it is the place where we play; it provides the snow for our winter recreation, and it provides the habitat for much of our wildlife. Water in contemporary American society is more than a simple physical entity, its symbolic values, and noninstrumental uses are growing in significance. As with many Native American cultures, water is as much a symbol as it is something to extract and use in the production of commercial products. This book is about the issues associated with these symbolic values and uses of water: the challenges they present—in our language, in our allocation mechanisms, in our communication—the conflicts raised; and the potential for resolving the difficult, contentious and complex issues concerning the use of water for various purposes. It is as much about framing the questions about symbolic values of water as it is anything else. McCool, Stephen, F.; Clark, Roger N.; Stankey, George H., eds. Tue, 19 Feb 2008 11:10:00 PST Gen. Tech. Rep. PNW-GTR-729. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 246 p. Tiffany Dong