Supervisory Mathematical Statistician
400 N 34th St., Suite 201
Contact Ashley Steel
My research explores the role of variability in ecological systems. Currently I am working on a series of projects to understand and predict water temperature patterns in rivers. I maintain a monitoring array of water temperature sensors on the Snoqualmie River that have been recording data every 30-min for over six years and have been conducting experiments on the role of temperature fluctuations in early Chinook salmon life history. We apply spatial stream network models to understand what might be driving observed patterns of river temperature and to make predictions about facets of the thermal regime that matter to the fish, either in unmeasured parts of the river network or in the future. We are now collecting water samples for stable isotope analyses that will explore how the source of water, rain versus snow, is distributed on the network, how the distribution shifts by season, and how it may be altered with changing patterns of precipitation.
- Water temperature on river networks
- Landscape influences on rivers
- Communicating statistics and uncertainty
- Science and statistics education
My past research has included wavelet decomposition to quantify complex thermal regimes and establish the effects of dams on water temperature, the use of model sensitivity analysis on a complex salmon habitat model used in salmon recovery planning, development of a scenario-based decision-support tool that outputs spatially-explicit tradeoffs across river restoration strategies, and the linkage of landscapes to salmon distribution across watersheds.
Why This Research is Important
Variability is a fundamental element of ecological systems. Understanding how human actions might reduce or increase variability in, for example, river temperatures, is essential for informed watershed management. By quantifying and communicating uncertainty or variability in model output, scientists and managers can better understand the range of potential outcomes and the likelihood of particular desired or undesired results.
- University of Washington, Ph.D. Quantitative Ecology 1999
- University of Washington, M.S. Statistics 1996
- University of Washington, M.S. River Ecology 1993
- Duke University, B.S. Sociology 1988
Featured Publications & Products
- Steel, E. Ashley; Beechie, Timothy J.; Torgersen, Christian E.; Fullerton, Aimee H. 2017. Envisioning, quantifying, and managing thermal regimes on river networks.
- Harrington, Constance A.; Holub, Scott M.; Bauer, Cici; Steel, E. Ashley. 2017. The distribution of tree roots in Douglas-fir forests in the Pacific Northwest in relation to depth, space, coarse organic matter and mineral fragments..
- Fuhrman, Abby E.; Larsen, Donald A.; Steel, Ashley; Young, Graham; Beckman, Brian R. 2017. Chinook salmon emergence phenotypes: describing the relationships between temperature, emergence timing and condition factor in a reaction norm framework.
- Steel, E. Ashley; Muldoon, Ariel; Flitcroft, Rebecca L.; Firman, Julie C.; Anlauf-Dunn, Kara J.; Burnett, Kelly M.; Danehy, Robert J. 2017. Current landscapes and legacies of land-use past: understanding the distribution of juvenile coho salmon (Oncorhynchus kisutch) and their habitats along the Oregon Coast, USA.
- Miller, Mark P.; Haig, Susan M.; Ballou, Jonathan D.; Steel, Ashley. 2017. Estimating inbreeding rates in natural populations: addressing the problem of incomplete pedigrees.
- Mazza, Rhonda; Steel, Ashley. 2017. Fluid temperatures: Modeling the thermal regime of a river network.
- Turschwell, Mischa P.; Balcombe, Stephen R.; Steel, E. Ashley; Sheldon, Fran; Peterson, Erin E. 2017. Thermal habitat restricts patterns of occurrence in multiple life-stages of a headwater fish.
- Baker, Susan C.; Halpern, Charles B.; Wardlaw, Timothy J.; Kern, Christel; Edgar, Graham J.; Thomson, Russell J.; Bigley, Richard E.; Franklin, Jerry F.; Gandhi, Kamal J. K.; Gustafsson, Lena; Johnson, Samuel; Palik, Brian J.; Spies, Thomas A.; Steel, E. Ashley; Weslien, Jan; Strengbom, Joachim. 2016. A cross-continental comparison of plant and beetle responses to retention of forest patches during timber harvest.
- Zald, Harold S.J.; Spies, Thomas A.; Seidl, Rupert; Pabst, Robert J.; Olsen, Keith A.; Steel, Ashley. 2016. Complex mountain terrain and disturbance history drive variation in forest aboveground live carbon density in the western Oregon Cascades, USA.
- Caouette, John P.; Steel, Ashley E.; Hennon, Paul E.; Cunningham, Pat G.; Pohl, Cathy A.; Schrader, Barbara A. 2016. Influence of elevation and site productivity on conifer distributions across Alaskan temperate rainforests.
- Steel, Ashley E.; Sowder, Colin; Peterson, Erin E. 2016. Spatial and temporal variation of water temperature regimes on the Snoqualmie River network.
- Polivka, Karl M.; Steel, E. Ashley; Novak, Jenni L.; Jonsson, Bror. 2015. Juvenile salmon and steelhead occupancy of stream pools treated and not treated with restoration structures, Entiat River, Washington.
- Fullerton, Aimee H.; Torgersen, Christian E.; Lawler, Joshua J.; Faux, Russell N.; Steel, Ashley; Beechie, Timothy J.; Ebersole, Joseph L.; Leibowitz, Scott G. 2015. Rethinking the longitudinal stream temperature paradigm: region-wide comparison of thermal infrared imagery reveals unexpected complexity of river temperatures.
- Steel, E. Ashley; Beckman, Brian; Oliver, Marie. 2014. Stream temperature variability: why it matters to salmon.
- Hummel, Susan; Kennedy, Maureen; Steel, E. Ashley. 2012. Assessing forest vegetation and fire simulation model performance after the Cold Springs wildfire, Washington USA.
- O’Callaghan, Joan; Steel, Ashley E.; Burnett, Kelly M. 2012. Thinking big: linking rivers to landscapes.
- Anlauf, K.J.; Jensen, D.W.; Burnett, K.M.; Steel, E.A.; Christiansen, K.; Firman, J.C.; Feist, B.E.; Larsen, D.P. 2011. Explaining spatial variability in stream habitats using both natural and management-influenced landscape predictors.
- Fullerton, Aimee H.; Lindley, Steven T.; Pess, George R.; Feist, Blake E.; Steel, E. Ashley; McElhany, Paul. 2011. Human influence on the spatial structure of threatened Pacific salmon metapopulations.
- Firman, Julie C.; Steel, E. Ashley; Jensen, David W.; Burnett, Kelly M.; Christiansen, Kelly; Feist, Blake E.; Larsen, David P.; Anlauf, Kara. 2011. Landscape models of adult coho salmon density examined at four spatial extents.
- Lucero, Yasmin; Steel, E. Ashley; Burnett, Kelly M.; Christiansen, Kelly. 2011. Untangling human development and natural gradients: implications of underlying correlation structure for linking landscapes and riverine ecosystems.
- Fullerton, A.H.; Burnett, Kelly; Steel, Ashley; Flitcroft, Rebecca; Pess, G.R.; Feist, B.E.; Torgersen, C.E.; Miller, D.J.; Sanderson, B.L. 2010. Hydrological connectivity for riverine fish: measurement challenges and research opportunities.