NW Climate Science Digest

Aquatic Resources, Stream Flow, Hydrology in the Western U.S.

Restoring wetlands can lessen soil sinkage and greenhouse gas emissions

Jaclyn Hatala Matthes, Cove Sturtevant, Joseph Verfaillie, Sara Knox, Dennis Baldocchi. Parsing the variability in CH4flux at a spatially heterogeneous wetland: Integrating multiple eddy covariance towers with high-resolution flux footprint analysis. Journal of Geophysical Research: Biogeosciences, 2014; 119 (7): 1322 DOI: 10.1002/2014JG002642

Restoring wetlands can help reduce or reverse soil subsidence and reduce greenhouse gas emissions, according to research in California's Sacramento-San Joaquin River Delta. The study is one of the first to continually measure the fluctuations of both carbon and methane as they cycle through wetlands. 

Tracking Interannual Streamflow Variability with Drought Indicies in the US Pacific Northwest

Abatzoglou, J.T.; R. Barbero; J.W. Wolf; & Z. A. Holden. 2014. Tracking Interannual Streamflow Variability with Drought Indices in the U.S. Pacific Northwest. J. Hydrometeor, 15, 1900–1912. doi: http://dx.doi.org/10.1175/JHM-D-13-0167.1

Drought indices are often used to monitor interannual variability in regional pattern of hydrology, but approaches vary widely. This study correlated various indices to water-year runoff for 21 unregulated drainage basins in the Pacific Northwest of the United States to identify those indices that explain the greatest amount of variability. 

Relative effects of climate change and wildfires on stream temperatures

Holsinger, Lisa; Keane, Robert E.; Isaak, Daniel J.; Eby, Lisa; Young, Michael K. 2014. Climatic Change. Relative effects of climate change and wildfires on stream temperatures: A simulation modeling approach in a Rocky Mountain watershed. 2014. Climatic Change.  124: 191-206. Online: http://www.treesearch.fs.fed.us/pubs/46508.

The authors created a model using landscape fire and vegetation data and an equation that predicted daily stream temperatures to explore how climate change and its impacts on fire might affect stream temperature across a partially forested, mountainous landscape in the western U.S. The model provides insights into the roles that wildfire and management actions such as fuel reduction and fire suppression could play in mitigating stream thermal responses to climate change. 

Estimates of twenty-first-century flood risk in the Pacific Northwest based on regional climate model simulations

Eric P. Salathé Jr., Alan F. Hamlet, Clifford F. Mass, Se-Yeun Lee, Matt Stumbaugh, and Richard Steed, 2014: Estimates of Twenty-First-Century Flood Risk in the Pacific Northwest Based on Regional Climate Model Simulations. J. Hydrometeor, 15, 1881–1899. doi: http://dx.doi.org/10.1175/JHM-D-13-0137.1

Results from a regional climate model simulation show substantial increases in future flood risk (2040–69) in many Pacific Northwest river basins in the early fall. Two primary causes are identified: 1) more extreme and earlier storms and 2) warming temperatures that shift precipitation from snow to rain dominance over regional terrain. The simulations also show a wide range of uncertainty among different basins stemming from localized storm characteristics.

Arid Ecosystems

Sagebrush ecosystems and Greater Sage-Grouse habitat

Using resistance and resilience concepts to reduce impacts of invasive annual grasses and altered fire regimes on the sagebrush ecosystem and Greater Sage-Grouse: A strategic multi-scale approach. Chambers, Jeanne C.; Pyke, David A.; Maestas, Jeremy D.; Pellant, Mike; Boyd, Chad S.; Campbell, Steven B.; Espinosa, Shawn; Havlina, Douglas W.; Mayer, Kenneth E.; Wuenschel, Amarina. 2014. Gen. Tech. Rep. RMRS-GTR-326. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 73 p.  Online: http://www.fs.fed.us/rm/pubs/rmrs_gtr326.html

This report provides a strategic approach for conservation of sagebrush ecosystems and Greater Sage-Grouse (sage-grouse) that focuses specifically on habitat threats caused by invasive annual grasses and altered fire regimes. It uses information on factors that influence (1) sagebrush ecosystem resilience to disturbance and resistance to invasive annual grasses and (2) distribution, relative abundance, and persistence of sage-grouse populations to develop management strategies at both landscape and site scales. A sage-grouse habitat matrix links relative resilience and resistance of sagebrush ecosystems with sage-grouse habitat requirements for landscape cover of sagebrush to help decision makers assess risks and determine appropriate management strategies at landscape scales.

Effects of climate change on net primary production of US rangelands

Reeves, M.C.; Moreno, A.L.; Bagne, K.E.; & Running, S.W.  Estimating climate change effects on net primary production of rangelands in the United States.  2014.  Climatic Change.  Online: http://www.readcube.com/articles/10.1007/s10584-014-1235-8 DOI 10.1007/s10584-014-1235-8

Modeling and experimental results suggest that net primary productivity of grasslands of the interior west of the US will likely increase under future climate scenarios.  Increases will not likely be uniform across the region, as grasslands dominated by warm season species responded most to temperature while cool season dominated regions responded more strongly to CO2 enrichment.  

Sagebrush and piñon-juniper ecosystems: Field guide for treatment

Miller, Richard F.; Chambers, Jeanne C.; Pellant, Mike. A field guide for selecting the most appropriate treatment in sagebrush and piñon-juniper ecosystems in the Great Basin: Evaluating resilience to disturbance and resistance to invasive annual grasses, and predicting vegetation response. 2014. Gen. Tech. Rep. RMRS-GTR-322. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 66 p. Online: http://www.fs.fed.us/rm/pubs/rmrs_gtr322.html.

This field guide identifies seven primary components that largely determine resilience to disturbance, as well as resistance to invasive grasses and plant succession following treatment of areas of concern: (1) characteristics of the ecological site, (2) current vegetation prior to treatment, (3) disturbance history, (4) type, timing, and severity of the treatment, (5) post-treatment weather, (6) post-treatment management, especially grazing, and (7) monitoring and adaptive management. A series of key questions and a set of tools are provided to assess these primary components. This assessment is designed to allow field personnel to (1) evaluate resilience to disturbance and resistance to invasive annual grass for an area of concern, (2) predict the potential successional pathways, and (3) then select the most appropriate treatment, including the need for seeding.

Biodiversity/Species and Ecosystem Response

Winter bird communities in eastern North America are shifting, thanks partly to climate change

Princé, K. and B. Zuckerberg. 2014. Climate change in our backyards: the reshuffling of North America’s winter bird communities. Global Change Biology doi: 10.1111/gcb.12740.

Species that typically prefer warmer weather, such as chipping sparrows, Carolina wrens, and eastern bluebirds, are advancing north.

Climate and Weather Reports and Services

Worst MegaDrought in 1,000 years

Hannah Hoag, Oct 16, 2014, Nature News, doi:10.1038/nature.2014.16157 synthesizes four journal articles]: http://www.nature.com/news/us-dust-bowl-unrivalled-in-past-1-000-years-1.16157

Using the North American Drought Atlas, a 2,005-year record derived from tree-ring chronologies that reconstructs drought and precipitation patterns, researchers have found that the 1934 drought that covered more than 70% of western North America and was 30% more intense than the second most severe drought in the region, which happened in 1580…. The cause is attributed to a high-pressure ridge that blocked wet weather from California and the Northwest….  A similar, but more persistent, atmospheric pattern was at work off the California coast this past winter, moving storms north, and research is tracing this recent event to human-made warming of the western Pacific Ocean.

Coastal/Marine Ecosystems, Ocean Acidification, Sea Level Rise

New research quantifies what’s causing sea level to rise

Purkey, S. G., G. C. Johnson and D. P. Chambers.  2014.  Relative contributions of ocean mass and deep steric changes to sea level rise between 1993 and 2013.  Journal of Geophysical Research: Oceans.  DOI: 10.1002/2014JC010180 Online: http://www.skepticalscience.com/new-research-quantifies-sea-level-rise.html http://onlinelibrary.wiley.com/doi/10.1002/2014JC010180/abstract

Changes to sea level are mainly caused by thermal expansion of ocean waters as they heat, changes to the saltiness of water, and by an increase in ocean waters as ice melts and flows into the sea. The total annual sea level rise is about 3 mm per year – the question is, how much of that is from expansion and how much is from melting?  This research found that amount of heating decreases with ocean depth but that every water layer, even the deepest waters, have contributed some to sea level rise. The authors also report that the sea level rise contribution from the layers 300-2000 meters is much more than previously reported.

The web site for the Salish Sea Marine Survival Project is now live

 The site provides details about a new, comprehensive, international research effort to determine the primary factors affecting the survival of juvenile salmon and steelhead in the Salish Sea. The launch was made possible with help from Pacific Salmon Commission’s Southern Fund Committee, Washington State, and 40+ other federal, state, tribal, and academic project partners and public and private funders.  


Recent mountain pine beetle outbreaks, wildfire severity, and postfire tree regeneration in the US Northern Rockies

Harvey, B.J.; Donato, D.C.; Turner, M.G. 2014. Recent mountain pine beetle outbreaks, wildfire severity, and postfire tree regeneration in the US Northern Rockies. PNAS. Online: http://www.eenews.net/assets/2014/09/29/document_pm_02.pdf

This study investigated the potential relationship between bark beetle outbreak and ecological severity of wildfire. Surprisingly the authors found no relation of recent (2001-2010) beetle outbreak to subsequent fire severity. Instead fire severity was driven primarily by extreme burning conditions (weather) and topography.

Vulnerability of Bull Trout in the Face of Wildfires and Climate Change

Falke, J.A., Flitcroft, R.L., Dunham, J.B., McNyset, K.M., Hessburg, P.F., Reeves, G.H., 2014, Climate change and vulnerability of bull trout (Salvelinus confluentus) in a fire-prone landscape. DOI- 10.1139/cjfas-2014-0098: Canadian Journal Fisheries and Aquatic Sciences, p. online. 

In the Pacific Northwest, climate change is anticipated to result in increased frequency, severity, and size of wildfires. Large and severe wildfires can lead to higher stream temperatures, affecting fish that rely on cold water to survive, such as the threatened bull trout. To address this issue, Oregon State University, U.S. Forest Service, and USGS researchers modeled population vulnerability of bull trout in the Wenatchee River, WA under current and future climate and fire scenarios. Analyses showed that local management, including reducing fire size and removing barriers to enhance fish population connectivity, can significantly reduce the vulnerability of bull trout to climate change. The Wenatchee River basin represents a unique configuration of threats, but many of the fundamental processes modeled occur across the range of bull trout and lessons learned may be useful in other locations. 

Temperate and boreal forest mega-fires: characteristics and challenges

Stephens, Scott L.; Burrows, Neil; Buyantuyev, Alexander; Gray, Robert W.; Keane, Robert E.; Kubian, Rick; Liu, Shirong; Seijo, Francisco; Shu, Lifu; Tolhurst, Kevin G.; Ivan Wagtendonk, Jan W. 2014. Temperate and boreal forest mega-fires: characteristics and challenges. Frontiers in Ecology and the Environment. 12: 115-122. Online: http://www.treesearch.fs.fed.us/pubs/47021.

Three factors - climate change, fire exclusion, and antecedent disturbance, collectively referred to as the "mega-fire triangle" - likely contribute to today's mega-fires. Some characteristics of mega-fires may emulate historical fire regimes and can therefore sustain healthy fire-prone ecosystems, but other attributes decrease ecosystem resiliency. A good example of a program that seeks to mitigate mega-fires is located in Western Australia, where prescribed burning reduces wildfire intensity while conserving ecosystems. Fire and forest managers should recognize that mega-fires will be a part of future wildland fire regimes and should develop strategies to reduce their undesired impacts.

A spatial database of wildfires in the United States, 1992-2011

Short, K.C. 2014. A spatial database of wildfires in the United States, 1992-2011. Earth System Science Data. 6: 1-27. Online: http://www.treesearch.fs.fed.us/pubs/45689.

This project represents an attempt to acquire, standardize, error-check, compile, scrub, and evaluate the completeness of US federal, state, and local wildfire records from 1992-2011 for the national, interagency Fire Program Analysis (FPA) application. The resulting FPA Fire-Occurrence Database (FPA FOD) includes nearly 1.6 million records from the 20-year period, with information about location, discovery date, and final fire size. While necessarily incomplete in some aspects, the database is intended to facilitate fairly high-resolution geospatial analysis of US wildfire activity over the past two decades, based on available information from the authoritative systems of record.

Regional projections of the likelihood of very large wildland fires under a changing climate in the contiguous Western United States

Stavros, E.N.; Abatzoglou, J.T.; McKenzie, D.; Larkin, N.K.  2014. Regional projections of the likelihood of very large wildland fires under a changing climate in the contiguous Western United States. Climatic Change.

http://link.springer.com/article/10.1007%2Fs10584-014-1229-6 DOI 10.1007/s10584-014-1229-6

Seasonal changes in the climatic potential for very large wildfires across the western contiguous United States are projected over the 21st century. The probability of large wildfires will likely increase under multiple climate scenarios. Modelng suggests the largest increases will be in the Eastern Great Basin, Northern Rockies, Pacific Northwest, Rocky Mountains, and Southwest. Changes in seasonality and frequency of large wildfires depend on changes in the future climate space. For example, flammability-limited areas such as the Pacific Northwest show greater increases in large fire probability than fuel-limited systems like the Western Great Basin. These results provide a quantitative foundation to help mitigate the effects of large wildfires.

Economics of wildfire management: The development and application of suppression expenditure models

Hand, Michael S.; Gebert, Krista M.; Liang, Jingjing; Calkin, David E.; Thompson, Matthew P.; Zhou, Mo. 2014. Economics of wildfire management: The development and application of suppression expenditure models. Springer Briefs In Fire. New York, NY: Springer. 71 p. Online: http://www.treesearch.fs.fed.us/pubs/46341.

In the United States, increased wildland fire activity over the last 15 years has resulted in increased pressure to balance the cost, benefits, and risks of wildfire management. This book examines the state-of-the-art in the economics of wildfire management. The introductory chapter presents the broad goal of the book: to take stock of research to-date on the economics of wildfire management and examine a way forward for answering remaining research questions. Subsequent chapters review existing research, present new empirical analyses of fire management expenditures, and examine potential applications of expenditure models for decision making.

A spatial stochastic programming model for timber and core area management under risk of fires

Wei, Yu; Bevers, Michael; Nguyen, Dung; Belval, Erin. 2014. A spatial stochastic programming model for timber and core area management under risk of fires. Forest Science. 60(1): 85-96. Online: http://www.treesearch.fs.fed.us/pubs/46563.

This study analyzed the effect of random stand-replacing fire on the implications of various harvest and mature forest core area decisions for forests. Results indicate that integrating the occurrence of stand-replacing fire into forest harvest scheduling models can improve the quality of long-term spatially explicit forest plans.


Co-occurring Ponderosa pine and Douglas fir respond differently to environmental factors associated with future climate change

Soule, P.T. & P.A. Knapp.  2014.  Analyses of intrinsic water-use efficiency indicate performance differences of ponderosa pine and Douglas-fir in response to CO2 enrichment.  Journal of Biogeography.  DOI: 10.1111/jbi.12408 online: http://onlinelibrary.wiley.com/doi/10.1111/jbi.12408/abstract

A suite of recent publications in Forest Ecology and Management and an article in Journal of Biogeography address the different ways in which locally co-occurring Ponderosa pine and Douglas fir respond to environmental factors such as CO2 enrichment,


Soule and Knapp analyzed patterns of water use efficiency for co-occurring Ponderosa pine and Douglas fir from 1850 to the present.  They found that both species have increased exponentially increasing rates of water use efficiency but that increases were greater for Ponderosa pine and that the relationship between water use efficiency and basal area increment differed between the two species.

Drought-triggered western spruce budworm outbreaks in the Interior Pacific Northwest

Flower, A.; Gavin, D.G.; Heyerdahl, E.K.; Parsons, R.A.; Cohn, G.M. 2014. Drought-triggered western spruce budworm outbreaks in the Interior Pacific Northwest: A multi-century dendrochronological record. Forest Ecology and Management. 324: 16-27. Online: http://www.treesearch.fs.fed.us/pubs/47005.

Western spruce budworms are considered the most destructive defoliator in western North America. This study analyzed patterns of their outbreak in Douglas fir forests from central Oregon to western Montana over the last three centuries in relation to regional drought history.  The authors found that outbreaks tend to occur near the end of droughts, indicating that climate is an important driver of outbreaks and that outbreaks will likely become more frequent in the future. 

Land Use

Rangelands as Carbon Sinks to Mitigate Climate Change: A Review

McDermot C, Elavarthi S (2014) Rangelands as Carbon Sinks to Mitigate Climate Change: A Review. J Earth Sci Clim Change 5:221. doi: 10.4172/2157-7617.1000221

Rangelands cover large areas in the United States and, when properly managed and maintained, can help mitigate climate change by sequestering substantial amounts of atmospheric carbon dioxide in the form of soil organic carbon.  The voluntary carbon market was a good approach for stimulating carbon sequestration on rangelands, however the causes of failures should be revisited, addressed and necessary amendment to policies made that will drive environmental restoration and conservation.

Special Reports / Announcements

The U.S. Environmental Protection Agency (EPA) released the third edition of 'Climate Change Indicators in the United States

The report pulls together observed data on key measures of our environment, including U.S. and global temperature and precipitation, ocean heat and ocean acidity, sea level, length of growing season, and many others. With 30 indicators that include over 80 maps and graphs showing long-term trends, the report demonstrates that climate change is already affecting our environment and our society. The third edition of the Indicators report includes four new indicators: Lyme disease, heating and cooling degree days, wildfires, and water level and temperature in the Great Lakes. In addition, the report adds four new features that connect observed data records to local communities and areas of interest, including cherry blossom bloom dates in Washington D.C., timing of ice breakup in two Alaskan rivers, temperature and drought in the Southwest, and land loss along the mid-Atlantic coast.
More information about the Climate Change Indicators report.

Taking Action

EPA Grants to Drought-Stricken Southwest Tribes Total $43 Million

Situating adaptation: How governance challenges and perceptions of uncertainty influence adaptation in the Rocky Mountains. Wyborn, Carina; Yung, Laurie; Murphy, Daniel; Williams, Daniel R. 2014. Regional Environmental Change. doi:10.1007/s10113-014-0663-3. Online: http://www.treesearch.fs.fed.us/pubs/46725.

This publication provides much needed guidance for conducting risk-based climate change vulnerability assessments and developing adaptation action plans. The workbook helps users to identify, analyze and prioritize climate change risks. In developing an action plan, it guides users to address their most pressing risks and find appropriate responses. Climate change, once considered an issue for a distant future, has moved firmly into the present. By using the workbook and addressing climate change in their systems, users will be ready to protect environmental resources, public safety, and infrastructure. Learn more about the Being Prepared for Climate Change workbook tools to help increase resiliency and tackle climate change in your own place. http://www2.epa.gov/cre/risk-based-adaptation

More than 100 Washington businesses call for strong action on Climate Change by signing The Washington Business Climate Declaration

The Washington Business Climate Declaration (www.climatedeclaration.us/wa) was developed by several Washington companies seeking to illustrate the state business community’s strong support for taking action to address climate change at the state and regional level and to mobilize strong business support to advance Washington’s economic and energy security. Starting with support from over 80 companies, the Washington Business Climate Declaration was developed as a rolling call to action, urging the public, policymakers and other business leaders to seize the opportunity to advance the Washington’s economic and energy security by tackling climate change