NW Climate Science Digest

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

Avalanche fatalities during atmospheric river events in the western US

Hatchett, B.J., Burak, S., Rutz, J.J., Oakley, N.S., Bair, E.H. and Kaplan, M.L., 2017. Avalanche Fatalities During Atmospheric River Events in the Western United States. Journal of Hydrometeorology. DOI: http://dx.doi.org/10.1175/JHM-D-16-0219.1

A new study led by the Desert Research Institute examined the relationship between atmospheric river occurrence and avalanche fatalities in the western United States from 1998 to 2014. They found atmospheric river conditions to be apparent during or preceding 105 avalanches that resulted in a total of 123 fatalities. Geographical distribution of these fatalities show the highest percentage coinciding with coastal snow avalanche climates, followed by intermountain and then continental snow avalanche climates. Findings from this study show that the intensity of inland water vapor transport could help identify periods of heightened avalanche hazard.

Slower snowmelt in a warmer world

Musselman, K.N., Clark, M.P., Liu, C., Ikeda, K. and Rasmussen, R., 2017. Slower snowmelt in a warmer world. Nature Climate Change. doi:10.1038/nclimate3225

Based on observations that shallower snowpack melts earlier and at lower rates than deeper, later-lying snow-cover, a team of scientists tested their hypothesis that a warmer climate would reduce snowmelt rates. Using climate model simulations, the authors examined the effect of warmer temperatures on snowmelt and found that the fraction of meltwater volume produced at high snowmelt rates was greatly reduced under warmer conditions. The authors concluded that this phenomenon is due to the shift of snowmelt season toward a time of lower available energy, which consequently reduces snow-covered areas exposed to enough energy to drive snowmelt by approximately 64 percent.

Evaluation of snowfall products over the western US

Wen, Y., Kirstetter, P., Gourley, J.J., Hong, Y., Behrangi, A. and Flamig, Z., 2017. Evaluation of MRMS snowfall products over the western United States. Journal of Hydrometeorology.

This recently published study assessed the success of Multi-Radar Multi-Sensor (MRMS) quantitative estimates of snow rate using Snow Telemetry (SNOTEL) daily snow water equivalent (SWE) datasets. The team of researchers found that MRMS displayed limited effectiveness in detecting very light snow (accumulation <5 mm), however exhibited good detectability of accumulation greater than 10 mm. This evaluation showed an underestimation bias of the monitoring system and the authors concluded that this bia is likely due to a problem with the calculation of the relationship between reflectivity and SWE intensity.

Measurements by school pupils paved way for key research findings on lakes and global warming

Gesa A. Weyhenmeyer, Murray Mackay, Jason D. Stockwell, Wim Thiery, Hans-Peter Grossart, Pétala B. Augusto-Silva, Helen M. Baulch, Elvira de Eyto, Josef Hejzlar, Külli Kangur, Georgiy Kirillin, Don C. Pierson, James A. Rusak, Steven Sadro, R. Iestyn Woolway. 2017. Citizen science shows systematic changes in the temperature difference between air and inland waters with global warming. Scientific Reports, 7: 43890 DOI: 10.1038/srep43890

High school students from Sweden conducted a citizen science project and, in collaboration with Uppsala University, produced key results for understanding the effect of increased warming on lake ecologies. Measurements of heat flux were collected by 3,500 Swedish students by examining the temperature difference between surface water and overlying air. The students were able to identify whether the lake was a source or sink of greenhouse gases and found that, in fact, heat flux was found to be increasingly negative with further warming. That is, as the overlying air is increasing in temperature, the lake surface water seems to be staying substantially colder. This observed mechanism could serve as a reduction of greenhouse gas transfer into the atmosphere.

Arid Ecosystems

Great Basin Landscape Conservation Cooperative’s 2017 Public Forum Feedback Summary now available

The Great Basin Landscape Conservation Cooperative (GBLCC) recently published a report summarizing feedback obtained in an online Public Forum that the GBLCC hosted from Jan. 23 – Feb. 8, 2017. During that time more than 230 people visited the interactive website to learn about recent GBLCC efforts and provide feedback on ideas for future work. The report highlights ideas and comments provided by Public Forum visitors on several topics, including: prioritization of the Great Basin LCC’s key objectives; ideas for new Steering Committee members; rangeland fire prevention and management; improving the resiliency of Great Basin forests and woodlands; opportunities for partnering with Great Basin tribes; and future webinar topics and information sharing efforts.

2016 Annual Great Basin Landscape Conservation Cooperative (GBLCC) Highlights Report now available

The GBLCC recently released its annual report for 2016. Highlights include being a primary source of science for the Integrated Rangeland Fire Management Strategy; playing an integral role in developing the Rangeland Fire Science Plan; helping develop an online science information portal for managers tackling rangeland research across the Great Basin; investing over $1 million in new research projects and a new traditional knowledge initiative; co-hosting the 2016 Great Basin Consortium Conference, attended by 500 people; undertaking the Northwest Basin and Range Synthesis Project to identify shared priorities across a common landscape; supporting Great Basin tribes; and hosting their most popular webinar series to date.

Biodiversity/Species and Ecosystem Response

Pattern of mammal dwarfing during global warming

Abigail R. D’Ambrosia, William C. Clyde, Henry C. Fricke, Philip D. Gingerich, Hemmo A. Abels. Repetitive mammalian dwarfing during ancient greenhouse warming events. Science Advances, 2017; 3 (3): e1601430 DOI: 10.1126/sciadv.1601430

A team of scientists examined the effect of Paleocene-Eocene global warming on mammalian body size. Due to the fact that smaller body size allows faster cool down, as well as increased efficiency in nutrient intake, smaller body size became favored by evolution under extreme warming. The authors quantified the relationship between mammalian body size and the intensity of warming events, and were able to identify the possible effects present anthropogenic climate change could have on this mechanism of adaptation.

Microbes measure ecological restoration success

Nicholas J.C. Gellie, Jacob G. Mills, Martin F. Breed, Andrew J. Lowe. Revegetation rewilds the soil bacterial microbiome of an old field. Molecular Ecology, 2017; DOI: 10.1111/mec.14081

Scientists from the University of Adelaide in Australia have published a new method for monitoring ecological restoration sites. Called “high-throughput amplicon sequencing of environmental DNA (eDNA),” the technique examines changes in the composition of DNA found within the soil of a newly revegetated site. Using this method, the scientists were able to map a timeline of microbial recovery. In an old field that had been grazed for 100 years, the study showed full recovery of the microbial community after 8 years of restoration. The authors emphasized the importance of supplementing restoration monitoring plans with eDNA methods in order to gain a detailed understanding of the restoration process.

Foundation of aquatic life can rapidly adapt to global warming

C.-Elisa Schaum, Samuel Barton, Elvire Bestion, Angus Buckling, Bernardo Garcia-Carreras, Paula Lopez, Chris Lowe, Samraat Pawar, Nicholas Smirnoff, Mark Trimmer, Gabriel Yvon-Durocher. 2017. Adaptation of phytoplankton to a decade of experimental warming linked to increased photosynthesis. Nature Ecology & Evolution; 1: 0094 DOI: 10.1038/s41559-017-0094

A team of scientists from the University of Exeter discovered formerly unknown adaptation mechanisms of phytoplankton. In this recently published study, scientists investigated the response of one species of green algae, Chlamydomonas reinhardtii, to warming in a 10-year-long laboratory experiment. The study found phytoplankton in the warmer environment displayed increased fitness in the new thermal conditions compared to phytoplankton from non-elevated temperatures. This result shows the capability of phytoplankton to rapidly adapt to warming. In particular, their evolutionary response consisted of producing higher rates of photosynthesis and therefore more energy, faster growth, and increased fitness. In an interview, scientist and lead author Elisa Schaum concluded, “although the green algae monitored in our study cope well with elevated temperature, and may be able to sustain populations of organisms that eat them, we do not know yet what will happen to other groups of algae, and whether or not they will adapt through the same mechanisms.”

Rapid evolution may help some city creatures stand the heat

Diamond SE  et al. 2017. Rapid evolution of ant thermal tolerance across an urban-rural temperature cline. Biological Journal of the Linnean Society.

Researchers from Case Western Reserve University in Ohio recently published a comparative study of the evolution of thermal tolerance in urban-rural acorn ants (Temnothorax curvispinosus). The study monitored ant colonies under urban and rural heat conditions. As urban environments are characterized by warmer temperatures, urban ant colonies exhibited more heat tolerance than rural ant colonies. This display of rapid adaption shows both fast-paced evolution as well as phenotypic plasticity within the species’ genome. Lead author Sarah Diamond stated, “Global data suggests that the acclimation response won’t be enough to respond to climate change, but some species, like the acorn ants, may evolve quickly enough.”

Climate and Weather Reports and Services

Tracking the start of the spring season across the country using Spring Leaf and Bloom Indices

The USA National Phenology Network (USA-NPN) tracks the start of the spring season across the country using models called the Spring Leaf and Bloom Indices.  The Spring Leaf Index is a synthetic measure of early season events like the first appearance of tiny leaves on trees, or crocus plants emerging from the snow, based on recent temperature conditions. This model allows scientists to track the progression of spring onset across the country. In 2017, USA-NPN saw very large anomalies in the United States on the Spring Leaf Index map, where the Index was met up to three weeks earlier than what is typical (1981-2010) in the southeast and almost equally late in the Northwest.

Soils could release much more carbon than expected as climate warms

Caitlin E. Hicks Pries, C. Castanha, R. Porras, M. S. Torn. The whole-soil carbon flux in response to warming. Science, 2017; eaal1319 DOI: 10.1126/science.aal1319

Scientists from the Department of Energy’s Lawrence Berkeley National Laboratory conducted an unprecedented field experiment, examining the impact of warming on the organic carbon content in soils. They found that CO2 production from all soil depths increased significantly with 4℃ warming. While most in-situ experiments only monitor warming of the surface soil, this study showed that all depths responded to warming with similar temperature sensitivities. Lead author Caitlin Hicks Pries stated, "if our findings are applied to soils around the globe that are similar to what we studied, meaning soils that are not frozen or saturated, our calculations suggest that by 2100 the warming of deeper soil layers could cause a release of carbon to the atmosphere at a rate that is significantly higher than today, perhaps even as high as 30 percent of today's human-caused annual carbon emissions depending on the assumptions on which the estimate is based.”

Coastal/Marine Ecosystems, Ocean Acidification, Sea Level Rise

New Technique Quickly Predicts Salt Marsh Vulnerability

A USGS-led team of researchers has developed a convenient tool for land managers to assess the vulnerability of coastal salt marshes. The method compares the ratio of ponds, channels, and tidal flats to marsh vegetation to act as a surrogate for more intensive assessment methods. The technique was tested in eight already-studied marshes, and the team discovered every marsh they assessed to be losing ground. Refuge manager, Bill Peterson, stated that the new tool “will help us figure out where we can make a difference with restoration techniques. It will also help us determine which areas are beyond restoration. This ensures that we’re using our limited resources effectively to strengthen and enhance these valuable natural areas.”

Helping Communities Understand Future Coastal Hazards: USGS Coastal Processes Team develops a publicly available coastal storm modeling system for California residents

On the west coast of the United States, the USGS Pacific Coastal and Marine Science Center’s Coastal Processes Team, led by Patrick Barnard and a group of 10 modelers, geologists, engineers, and oceanographers, has developed the Coastal Storm Modeling System (CoSMoS) to help the 20 million residents of California coastal communities understand their vulnerabilities from storms and sea-level rise. CoSMoS is a state-of-the-art modeling system that models all the relevant physics of a coastal storm (for example, tides, waves, and storm surge), which are then scaled down to local flood projections. Rather than relying on historic storm records, CoSMoS uses wind and pressure from global climate models to project coastal storms under changing climatic conditions. Projections of multiple storm scenarios (daily conditions, annual storm, 20-year- and 100-year-return intervals) are provided under a suite of sea-level rise scenarios ranging from 0 to 2 meters (0 to 6 feet), along with a catastrophic 5-meter (16-foot) scenario. This allows users to manage and meet their own planning horizons and specify degrees of risk tolerance.


Spatiotemporal dynamics of simulated wildfire, forest management, and forest succession in central Oregon, USA

Barros, A. M. G., A. A. Ager, M. A. Day, H. K. Preisler, T. A. Spies, E. White, R. Pabst, K. A. Olsen, E. Platt, J. D. Bailey, and J. P. Bolte. 2017. Spatiotemporal dynamics of simulated wildfire, forest management, and forest succession in central Oregon, USA. Ecology and Society 22(1):24.

Authors analyzed long-term wildfire dynamics and the effects of different fuel management scenarios in central Oregon, USA. Results showed that managing the forest to reduce fuels resulted in it burning less: over the course of 50 years there was up to a 40% reduction in area burned. However, area burned did not decrease progressively with time, nor did the absence of management lead to its increase. These results can be explained as the consequence of an existing wildfire deficit and vegetation succession paths that led to closed canopy, and heavy fuels forest types that are unlikely to burn under average fire weather. Doubling and tripling current management targets were effective at reducing fire in the near term but not sustainable over time because of a scarcity of stands eligible to treat according to the modeled management constraints. These results provide new insights into the long-term dynamics between fuel management programs and wildfire, demonstrating that treatment prioritization strategies have limited effect on fire activity if they are too narrowly focused on particular forest conditions.

Adapting fuel treatments in a changing climate - Prescribed fire, mechanical treatments, wildfire, and restoration

The Available Science Assessment Project (ASAP) leads, EcoAdapt and Oregon State University’s Institute for Natural Resources, have published a summary of a workshop they hosted last April during the International Association of Wildland Fire’s 5th Fire Behavior and Fuels Conference, in cooperation with the Northwest Fire Science Consortium and the Northern Rockies Fire Science Network. Thirty-six managers and scientists from 30 organizations attended the workshop, representing a range of federal and state agencies, tribal governments, non-profits, universities, and other research organizations. The workshop explored on-the-ground climate adaptation actions that might be used for fire and fuels management under future climate conditions. Specifically, workshop participants were asked to identify the likely impacts of climate change and what they saw as barriers and potential opportunities for the use of four management actions: prescribed fire;  mechanical fuel treatment; managed wildfire; and post-fire restoration (seeding/planting). Their responses are summarized in this short report. The ASAP project was funded in part by the Northwest Climate Science Center.

Using an agent-based model to examine forest management outcomes in a fire-prone landscape in Oregon, USA

Spies, T. A., E. White, A. Ager, J. D. Kline, J. P. Bolte, E. K. Platt, K. A. Olsen, R. J. Pabst, A. M.G. Barros, J. D. Bailey, S. Charnley, J. Koch, M. M. Steen-Adams, P. H. Singleton, J. Sulzman, C. Schwartz, and B. Csuti. 2017. Using an agent-based model to examine forest management outcomes in a fire-prone landscape in Oregon, USA. Ecology and Society 22(1):25.

Authors used a coupled human and natural systems framework and an agent-based landscape model to examine how alternative management scenarios affect fire and ecosystem services in a fire-prone multi-ownership landscape in the eastern Cascades of Oregon. Their model combined existing models of vegetation succession and fire spread with information from original empirical studies of landowner decision making. Results indicated that alternative management strategies can have variable effects on landscape outcomes over 50 years for fire, socioeconomic, and ecosystem services metrics. Federal restoration treatments slightly reduced threat various from fire, particularly in years with more fire. Under the current management scenario, timber production could be maintained for at least 50 years on federal lands. Under an accelerated restoration scenario, timber production fell because of a shortage of areas meeting current stand structure treatment targets. Trade-offs were evident between restoration goals (e.g., open forests with large fire-resistant trees) and protecting habitat for species that require dense older forests. For example, the proportional area of nesting habitat for northern spotted owl (Strix occidentalis) was somewhat reduced after 50 years under the restoration scenarios as compared to no management. However, the amount of resilient older forest structure and habitat for white-headed woodpecker (Leuconotopicus albolarvatus) was higher after 50 years under active management. More carbon was stored on this landscape without management than with management, despite the occurrence of high-severity wildfire. The authors suggest that further applications of their model could facilitate the development of policies and practices for fire-prone landscapes.


Landscape-scale quantification of fire-induced change in canopy cover following mountain pine beetle outbreak and timber harvest

T.R. McCarley, C.A. Kolden, N.M. Vaillant, A.T. Hudak, A.M.S.Smith, J.Kreitler. 2017. Landscape-scale quantification of fire-induced change in canopy cover following mountain pine beetle outbreak and timber harvest. Forest Ecology and Management: 391, 164–175.

Across the western United States, the three primary drivers of tree mortality and carbon balance are bark beetles, timber harvest, and wildfire. This study used pre- and post-fire Light Detection and Ranging (LiDAR) data on the 2012 Pole Creek Fire in central Oregon to isolate and quantify fire effects coincident with these specific agents of change. Observed canopy loss from fire was greater (higher severity) in areas experiencing pre-fire mountain pine beetle than fire-only. Additionally, increasing mountain pine beetle intensity was directly related to greater canopy loss. Canopy loss was lower for all areas of pre-fire timber harvest than for fire-only, but among harvested areas, the greatest change was observed in the oldest treatments and the most intensive treatments. These results highlight the importance of accounting for and understanding the impact of pre-fire agents of change such as mountain pine beetle and timber harvest on subsequent fire effects in land management planning. This work also demonstrates the utility of multi-temporal LiDAR as a tool for quantifying these landscape-scale interactions.

Forest management scenarios in a changing climate: trade-offs between carbon, timber and old forest

Creutzburg, M. K., Scheller, R. M., Lucash, M. S., LeDuc, S. D. and Johnson, M. G. (2017), Forest management scenarios in a changing climate: trade-offs between carbon, timber, and old forest. Ecol Appl, 27: 503–518. doi:10.1002/eap.1460

This study evaluated the long-term, landscape-scale trade-offs among carbon (C) storage, timber yield, and old forest habitat given projected climate change and shifts in forest management policy across 2.1 million hectares of forests in the Oregon Coast Range. Projections highlight the divergence between private and public lands under business-as-usual forest management, where private industrial forests are heavily harvested and many public (especially federal) lands increase C and old forest over time but provide little timber. Three alternative management scenarios altering the amount and type of timber harvest show widely varying levels of ecosystem C and old-forest habitat. On federal lands, ecological forestry practices also allowed a simultaneous increase in old forest and natural early-seral habitat. The ecosystem C implications of shifts away from current practices were large, with current practices retaining up to 105 Tg more C than the alternative scenarios by the end of the century. Results suggest that climate change is likely to increase forest productivity by 30–41% and total ecosystem C storage by 11–15% over the next century as warmer winter temperatures allow greater forest productivity in cooler months. These gains in C storage are unlikely to be offset by wildfire under climate change, due to the legacy of management and effective fire suppression. Authors suggest that these scenarios of future conditions can inform policy makers, land managers, and the public about the potential effects of land management alternatives, climate change, and the trade-offs that are inherent to management and policy in the region.

Developing a representative snow-monitoring network in a forested mountain watershed of the western Oregon Cascades

Gleason, K. E., Nolin, A. W., and Roth, T. R. 2017. Developing a representative snow-monitoring network in a forested mountain watershed, Hydrol. Earth Syst. Sci., 21, 1137-1147, doi:10.5194/hess-21-1137-2017

A study from Oregon State University offered a new method for identifying representative snow-monitoring locations in a forested watershed in the western Oregon Cascade mountain range. The team used a binary regression tree nonparametric statistical model and found that elevation and land cover type were the most significant drivers of spatial variability in peak snow water equivalent across the study area. This insight led to the development of the Forest Elevational Snow Transect tool which displays combinations of forested and open land cover types at various elevations. This tool will show a detailed dataset of snow accumulation, snow ablation, and snowpack energy balance across various landscapes of the western Oregon Cascades.

Land Use

A New Report from the Department of the Interior Highlights Remote Sensing Applications

Remotely sensed data and derived information contribute significantly to mission-critical work across the Department of the Interior (DOI). This report from the DOI Remote Sensing Working Group highlights a sample of DOI remote sensing applications and illustrates the many types of technology, platforms, and specialized sensors employed. DOI personnel use remote sensing technology to evaluate and monitor changing land-surface and natural resource conditions over the vast areas for which DOI has responsibility.

Tribal and Indigenous Peoples Matters

The impact of climate change on American and Canadian Indigenous Peoples and their water resources

Kornfeld, Itzchak E., The Impact of Climate Change on American and Canadian Indigenous Peoples and Their Water Resources: A Climate Justice Perspective (August 31, 2016). Available at SSRN: https://ssrn.com/abstract=2832879

This chapter in an upcoming book addresses threats faced by North American indigenous communities as a consequence of climate change. It highlights the fact that indigenous peoples in Canada and the United States, who live in extra-rural reservations and in remote and climate-vulnerable locations, will suffer much more than the non-indigenous populations in cities and the suburbs. Finally, the chapter offers some suggestions for mitigation and adaptation measures for indigenous communities. These recommendations include decreasing fossil fuel consumption through government action, imposing responsibility on corporations to reduce their carbon footprint and impact on human rights, and utilizing environmental justice case law precedent.

EPA public statement on South Fork Nooksack River climate research assessments

“Under the Clean Water Act, EPA reviews and either approves or disapproves TMDLs (Total Maximum Daily Load), which are submitted by states. A TMDL is the calculation of the maximum amount of a pollutant allowed to enter a water body so that it will meet and continue to meet water quality standards for that particular pollutant. Working with the Washington State Department of Ecology, the Nooksack Tribe and the Lummi Nation, EPA conducted a pilot study to assess how potential impacts of climate change on air temperature and streamflow could inform TMDL implementation in such a way as to make the TMDL more resilient to climate change. Data were collected from the South Fork Nooksack River in northwest Washington, where multiple water body segments currently exceed temperature criteria, and were used to estimate the temperature profile during projected summer low flow and elevated air temperatures. This externally peer-reviewed assessment includes estimates for a range of possible future temperature and weather conditions.  A second assessment provides an analysis of projected climate change impacts on freshwater habitat and salmon in the South Fork Nooksack River, and evaluates potential restoration actions. Findings are expected to be useful for informing salmon recovery, land use, and restoration planning efforts.”

1) Quantitative Assessment of Temperature Sensitivity of the South Fork Nooksack River Under Future Climates Using QUAL2Kw  

Butcher, J.B., M. Faizullabhoy, H. Nicholas, P. Cada, and J.T. Kennedy. 2016. Quantitative Assessment of Temperature Sensitivity of the South Fork Nooksack River Nooksack River under Future Climates using QUAL2Kw. EPA/600/R-14/233. Western Ecology Division, National Health and Environmental Effects Research Laboratory, Corvallis, OR.

The document may be found on the Science Inventory website at the following url: https://cfpub.epa.gov/si/si_public_record_Report.cfm?dirEntryId=288533.

2) Qualitative Assessment: Evaluating the Impacts of Climate Change on Endangered Species Act Recovery Actions for the South Fork Nooksack River, WA.

South Fork Climate Change Pilot, Qualitative Assessment on EPA’s Science Inventory

Environmental Protection Agency (EPA). 2016. Qualitative Assessment: Evaluating the Impacts of Climate Change on Endangered Species Act Recovery Actions for the South Fork Nooksack River, WA. EPA/600/R-16/153. Western Ecology Division, National Health and Environmental Effects Research Laboratory, Corvallis, OR.

The document may be found on the Science Inventory website at the following url: https://cfpub.epa.gov/si/si_public_record_Report.cfm?dirEntryId=320470.