Humboldt State University

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Dr. Alison Purcell O’Dowd

Associate Professor, Environmental Science Program Coordinator
Graduate Faculty

My teaching and research interests are in the restoration of damaged ecosystems and the ecology of freshwater systems. I currently teach courses in environmental science and ecological restoration. These courses investigate ways to address anthropogenic impacts and disturbances. I try to promote a learning atmosphere that allows students to interact with the natural environment and learn structural and functional processes first-hand. Therefore, I try to get my students outside as often as possible so they can fully experience the topic.

My research explores how biological stream communities (primarily benthic macroinvertebrates) respond to disturbance within a watershed. My bioassessment research uses benthic macroinvertebrates as indicators of water quality to develop indices for the management of water bodies. One of my research projects is the development of a muli-metric index for the Lake Tahoe Basin. Another project compared urban gradients and aquatic biological indicators of urbanization in three climatic regions of the United States: San Jose, CA (west coast); Baltimore, MD (Mid-Atlantic); and Cleveland, OH (Midwest). The biological indicators of urbanization developed for these three regions were intended to help water agencies prioritize restoration and conservation efforts in urban watersheds. My research has also involved several post- project assessments of urban stream restoration projects in the San Francisco Bay Area in order to evaluate their success. These assessments included biological, habitat, and sociological assessments of several urban stream restoration projects to determine the condition of each site over time.

I am also interested in the ecological significance of mountain step-pool streams. I am collaborating with a professor at the University of Colorado, Denver to compare biological communities in step-pool streams of northern California (Smith River) and Colorado.

My research at Humboldt State University also involves wetland ecosystems. My graduate students are exploring research questions related to an invasive non-native plant species (Spartina densiflora) in the salt marshes of Humboldt Bay.

I am thrilled to be teaching and conducting research in the fascinating and diverse ecological environment of the North Coast. Environmental issues are definitely at the forefront of people’s minds in this area..

Contact Information
Specialty Area

Ecological Restoration, Aquatic Ecology


Ph.D. University of California, Berkeley (Environmental Science, Policy, and Management/Aquatic Ecology)
B.S. University of Oregon, Eugene (Environmental Science)

Courses Taught

ENVS 110 – Introduction to Environmental Science
ENVS 230 – Environmental Problem Solving
ENVS 350 – Principles in Ecological Restoration
ENVS 450 – Applied Ecological Restoration

Research Interests

My research interests are within the areas of aquatic ecology and ecological restoration.  Specifically I study stream and wetland restoration, the ecology and eradication of invasive species, the impacts of wildfire on stream communities, and the biological significance of step-pool sequences in mountain streams. My research methods focus on using benthic macroinvertebrates as indicators of water quality in urban and natural freshwater ecosystems.


Chin, A., A. P. O’Dowd (Purcell), and K.J. Gregory. 2011. Urbanization in river systems. In: Fluvial Geomorphology (series called Treatise on Geomorphology, Geological Society of America), E. Wohl, ed., Amsterdam: Elsevier (in press).

O’Dowd (Purcell), A. P. 2011. Encouraging salmon recovery and restoring ecosystem function. California Forests Magazine 15(2):14-15.

Roy, A.H., A. H. Purcell, C. J. Walsh, and S. J. Wenger. 2009. Advances in urban stream ecology: an introduction to the series. Journal of the North American Benthological Society 28(4):908-910.

Carter, J. L., A. H. Purcell, S. V. Fend, and V. H. Resh. 2009. Development of a local-scale urban stream assessment method using benthic macroinvertebrates: an example from the Santa Clara Basin, California. Journal of the North American Benthological Society 28(4):1007-1021.

Wenger, S. J., A. H. Roy, C. R. Jackson, E. S. Bernhardt, T. L Carter, S. Filoso, C. A. Gibson, N. B. Grimm, W. C. Hession, S. S. Kaushal, E. Martí, J. L. Meyer, M. A. Palmer, M. J. Paul, A. H. Purcell, A. Ramirez, A. D. Rosemond, K. A. Schofield, E. Sudduth, and C. J. Walsh. 2009. Twenty-six key research questions in urban stream ecology: an assessment of the state of the science. Journal of the North American Benthological Society 28(4):1080-1098.

Chin, A., A. H. Purcell, J. Quan, and V.H. Resh. 2009. Assessing geomorphological and ecological responses in restored step-pool systems. In James, L.A., S.L. Rathburn, and G.R. Whittcar (eds.). Management and Restoration of Fluvial Systems with Broad Historical Changes and Human Impacts: Geological Society of America Special Paper 451, p. 199-217.

Bressler, D. W., M. J. Paul, A. H. Purcell, M. T. Barbour, E. Rankin, and V. H. Resh. 2009. Assessment tools for urban catchments: developing stressor gradients. Journal of the American Water Resources Association 45(2):291-305.

Purcell, A. H., D. W. Bressler, M. J. Paul, M. T. Barbour, E. Rankin, J. L. Carter, and V. H. Resh. 2009. Assessment tools for urban catchments: developing biological indicators using benthic macroinvertebrates. Journal of the American Water Resources Association 45(2):306- 319.

Paul, M. J., D. W. Bressler, A. H. Purcell, M. T. Barbour, E. Rankin, and V. H. Resh. 2009. Assessment tools for urban catchments: defining observable biological potential. Journal of the American Water Resources Association 45(2):320-330.

Mazor, R., A. H. Purcell, and V. H. Resh. 2009. Long-term variability in benthic macroinvertebrate bioassessments: A 20-year study from two northern Californian streams. Environmental Management 43:1269-1286.

Chin, A., S. Anerson, A. Collison, E. Ellis-Sugai, J.P. Haltiner, J.B. Hogervorst, G.M. Kondolf, L.S. O’Hirok, A.H. Purcell, A.L. Riley, and E. Wohl. 2009. Linking theory and practice for restoration of step-pool streams. Environmental Management 43:645-661.

Purcell, A. H., A. Hoffmann, and V. H. Resh. 2008. Life history of a dipteran predator (Scathophagidae: Acanthocnema) of insect egg masses in a northern California stream. Freshwater Biology 53:2426-2437.