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Christian E Torgersen

I am a Supervisory Research Landscape Ecologist at the Forest and Rangeland Ecosystem Science Center

My research interests include landscape ecology, riverine landscapes, watershed processes, ecological scaling, water quality, fish habitat, land use/land cover change, landscape scenario modeling, spatial analysis, remote sensing and GIS.

 

Professional Experience

  • 2005 - Present: USGS Forest and Rangeland Ecosystem Science Center, Supervisory Research Landscape Ecologist, Seattle, WA

  • 2002 - 2005: USGS Forest and Rangeland Ecosystem Science Center, Research Biologist, Corvallis, OR

Education and Certifications

  • Ph.D., Fisheries Science, Oregon State University, Corvallis, OR (2002)

  • M.S., Fisheries Science, Geography Minor, Oregon State University, Corvallis, OR (1996)

  • B.A., Geography/German, double major, University of Oregon, Eugene, OR (1993)

     

Science and Products

three scientists preparing to conduct an underwater biological survey

Aquatic & Landscape Ecology Research Team (FRESC)

Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
By
Forest and Rangeland Ecosystem Science Center
Aquatic & Landscape Ecology Research Team (FRESC)

Aquatic & Landscape Ecology Research Team (FRESC)

Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
Learn More

If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

No Result Found
No results found.

If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

Filter Total Items: 63

Diel horizontal migration in streams: juvenile fish exploit spatial heterogeneity in thermal and trophic resources Diel horizontal migration in streams: juvenile fish exploit spatial heterogeneity in thermal and trophic resources

Vertical heterogeneity in the physical characteristics of lakes and oceans is ecologically salient and exploited by a wide range of taxa through diel vertical migration to enhance their growth and survival. Whether analogous behaviors exploit horizontal habitat heterogeneity in streams is largely unknown. We investigated fish movement behavior at daily timescales to explore how...
Authors
Jonathan B. Armstrong, Daniel E. Schindler, Casey P. Ruff, Gabriel T. Brooks, Kale E. Bentley, Christian E. Torgersen
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Aquatic insect assemblages associated with subalpine stream segment types in relict glaciated headwaters Aquatic insect assemblages associated with subalpine stream segment types in relict glaciated headwaters

1. Aquatic habitats and biotic assemblages in subalpine headwaters are sensitive to climate and human impacts. Understanding biotic responses to such perturbations and the contribution of high-elevation headwaters to riverine biodiversity requires the assessment of assemblage composition among habitat types. We compared aquatic insect assemblages among headwater stream segment types in...
Authors
Joshua S. Kubo, Christian E. Torgersen, Susan M. Bolton, Anne A. Weekes, Robert I. Gara
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Spatial consistency of chinook salmon redd distribution within and among years in the Cowlitz River, Washington Spatial consistency of chinook salmon redd distribution within and among years in the Cowlitz River, Washington

We investigated the spawning patterns of Chinook Salmon Oncorhynchus tshawytscha on the lower Cowlitz River, Washington, using a unique set of fine- and coarse-scale temporal and spatial data collected during biweekly aerial surveys conducted in 1991–2009 (500 m to 28 km resolution) and 2008–2009 (100–500 m resolution). Redd locations were mapped from a helicopter during 2008 and 2009...
Authors
Katherine J.C. Klett, Christian E. Torgersen, Julie A. Henning, Christopher J. Murray
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Modelling dendritic ecological networks in space: anintegrated network perspective Modelling dendritic ecological networks in space: anintegrated network perspective

Dendritic ecological networks (DENs) are a unique form of ecological networks that exhibit a dendritic network topology (e.g. stream and cave networks or plant architecture). DENs have a dual spatial representation; as points within the network and as points in geographical space. Consequently, some analytical methods used to quantify relationships in other types of ecological networks...
Authors
Erin E. Peterson, Jay M. Ver Hoef, Dan J. Isaak, Jeffrey A. Falke, Marie-Josée Fortin, Chris E. Jordon, Kristina McNyset, Pascal Monestiez, Aaron S. Ruesch, Aritra Sengupta, Nicholas Som, E. Ashley Steel, David M. Theobald, Christian E. Torgersen, Seth J. Wenger
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Thermal infrared remote sensing of water temperature in riverine landscapes Thermal infrared remote sensing of water temperature in riverine landscapes

Water temperature in riverine landscapes is an important regional indicator of water quality that is influenced by both ground- and surface-water inputs, and indirectly by land use in the surrounding watershed (Brown and Krygier, 1970; Beschta et al., 1987; Chen et al., 1998; Poole and Berman, 2001). Coldwater fishes such as salmon and trout are sensitive to elevated water temperature...
Authors
R. N Handcock, Christian E. Torgersen, K. A Cherkauer, A. R Gillespie, K Tockner, R. N. Faux, Jing Tan
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Projected climate-induced habitat loss for salmonids in the John Day River network, Oregon, U.S.A. Projected climate-induced habitat loss for salmonids in the John Day River network, Oregon, U.S.A.

Climate change will likely have profound effects on cold-water species of freshwater fishes. As temperatures rise, cold-water fish distributions may shift and contract in response. Predicting the effects of projected stream warming in stream networks is complicated by the generally poor correlation between water temperature and air temperature. Spatial dependencies in stream networks are...
Authors
Aaron S. Ruesch, Christian E. Torgersen, Joshua J. Lawler, Julian D. Olden, Erin E. Peterson, Carol J. Volk, David J. Lawrence
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Non-USGS Publications**

Torgersen, C.E., Close, D.A., 2004, Influence of habitat heterogeneity on the distribution of larval Pacific lamprey (Lampetra tridentata) at two spatial scales: Freshwater Biology, v. 49, no. 5, p. 614-630.
Fausch, K.D., Torgersen, C.E., Baxter, C.V., Li, H.W., 2002, Landscapes to riverscapes- bridging the gap between research and conservation of stream fishes: BioScience, v. 52, no. 6, p. 483-498.
Torgersen, C.E., Faux, R.N., McIntosh, B.A., Poage, N., Norton, D.J., 2001, Airborne thermal remote sensing for water temperature assessment in rivers and streams: Remote Sensing of Environment, v. 76, p. 386-398.
Torgersen, C.E., Price, D.M., Li, H.W., McIntosh, B.A., 1999, Multiscale thermal refugia and stream habitat associations of chinook salmon in northwestern Oregon: Ecological Applications, v. 9, no. 1, p. 301-319, https://doi.org/10.1890/1051-0761(1999)009[0301:MTRASH]2.0.CO;2.
Torgersen, C.E., Poage, N., Flood, M., Norton, D.J., McIntosh, B.A., 1996, Airborne thermal remote sensing of salmonid habitat for restoration planning in Pacific Northwestern watersheds, Baltimore, MD In eds., Proceedings of the Watershed 96 Conference: Alexandria, VA, Water Environment Federation, p. 812-814.
Poage, N., Torgersen, C.E., Norton, D.J., Flood, M., McIntosh, B.A., 1996, Application of thermal infrared (FLIR) and visible videography to the monitoring and restoration of salmonid habitat in the Pacific Northwest In Greer, J.D., ed., Proceedings of the Sixth Forest Service Remote Sensing Applications Conference: Denver, CO, American Society for Photogrammetry and Remote Sensing, p. 376-379.
Torgersen, C.E., Jones, J.A., Moldenke, A.R., LeMaster, M.P., 1995, The spatial heterogeneity of soil invertebrates and edaphic properties in an old growth forest stand in western Oregon In Collins, H.P., Robertson, G.P., Klug, M.J., eds., The Significance and Regulation of Soil Biodiversity: Dordrecht, Netherlands, Kluwer Academic Publishers, p. 225-236.
Torgersen, C.E., Price, D.M., Li, H.W., McIntosh, B.A., 1995, Thermal refugia and chinook salmon habitat in Oregon- Applications of airborne thermal videography In Mausel, P., ed., Proceedings of the 15th Biennial Workshop on Color Photography and Videography: Terre Haute, IN, American Society for Photogrammetry and Remote Sensing, p. 167-171.
Torgersen, C.E., Baxter, C.V., Li, H., McIntosh, B.A., 2006, Landscape influences on longitudinal patterns of river fishes- Spatially continuous analysis of fish-habitat relationships In Hughes, R., Wang, L., Wofford, J.E., eds., Influences of Landscapes on Stream Habitats and Biological Assemblages: Bethesda, MD, American Fisheries Society, p. 473-492

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.

Science and Products

three scientists preparing to conduct an underwater biological survey

Aquatic & Landscape Ecology Research Team (FRESC)

Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
By
Forest and Rangeland Ecosystem Science Center
Aquatic & Landscape Ecology Research Team (FRESC)

Aquatic & Landscape Ecology Research Team (FRESC)

Fresh waters are one of the most valuable and threatened resources worldwide. They supply critical services to society and harbor many of the world’s most imperiled species. We conduct research and provide technical assistance to address challenges to fresh waters. Our research focuses on ecological processes in freshwater and terrestrial systems and the effects of those processes on landscape...
Learn More

If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

No Result Found
No results found.

If you are unable to access or download a product, email fresc_outreach@usgs.gov a request, including the full citation, or call (541) 750-1030.

Filter Total Items: 63

Diel horizontal migration in streams: juvenile fish exploit spatial heterogeneity in thermal and trophic resources Diel horizontal migration in streams: juvenile fish exploit spatial heterogeneity in thermal and trophic resources

Vertical heterogeneity in the physical characteristics of lakes and oceans is ecologically salient and exploited by a wide range of taxa through diel vertical migration to enhance their growth and survival. Whether analogous behaviors exploit horizontal habitat heterogeneity in streams is largely unknown. We investigated fish movement behavior at daily timescales to explore how...
Authors
Jonathan B. Armstrong, Daniel E. Schindler, Casey P. Ruff, Gabriel T. Brooks, Kale E. Bentley, Christian E. Torgersen
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Aquatic insect assemblages associated with subalpine stream segment types in relict glaciated headwaters Aquatic insect assemblages associated with subalpine stream segment types in relict glaciated headwaters

1. Aquatic habitats and biotic assemblages in subalpine headwaters are sensitive to climate and human impacts. Understanding biotic responses to such perturbations and the contribution of high-elevation headwaters to riverine biodiversity requires the assessment of assemblage composition among habitat types. We compared aquatic insect assemblages among headwater stream segment types in...
Authors
Joshua S. Kubo, Christian E. Torgersen, Susan M. Bolton, Anne A. Weekes, Robert I. Gara
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Spatial consistency of chinook salmon redd distribution within and among years in the Cowlitz River, Washington Spatial consistency of chinook salmon redd distribution within and among years in the Cowlitz River, Washington

We investigated the spawning patterns of Chinook Salmon Oncorhynchus tshawytscha on the lower Cowlitz River, Washington, using a unique set of fine- and coarse-scale temporal and spatial data collected during biweekly aerial surveys conducted in 1991–2009 (500 m to 28 km resolution) and 2008–2009 (100–500 m resolution). Redd locations were mapped from a helicopter during 2008 and 2009...
Authors
Katherine J.C. Klett, Christian E. Torgersen, Julie A. Henning, Christopher J. Murray
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Modelling dendritic ecological networks in space: anintegrated network perspective Modelling dendritic ecological networks in space: anintegrated network perspective

Dendritic ecological networks (DENs) are a unique form of ecological networks that exhibit a dendritic network topology (e.g. stream and cave networks or plant architecture). DENs have a dual spatial representation; as points within the network and as points in geographical space. Consequently, some analytical methods used to quantify relationships in other types of ecological networks...
Authors
Erin E. Peterson, Jay M. Ver Hoef, Dan J. Isaak, Jeffrey A. Falke, Marie-Josée Fortin, Chris E. Jordon, Kristina McNyset, Pascal Monestiez, Aaron S. Ruesch, Aritra Sengupta, Nicholas Som, E. Ashley Steel, David M. Theobald, Christian E. Torgersen, Seth J. Wenger
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Thermal infrared remote sensing of water temperature in riverine landscapes Thermal infrared remote sensing of water temperature in riverine landscapes

Water temperature in riverine landscapes is an important regional indicator of water quality that is influenced by both ground- and surface-water inputs, and indirectly by land use in the surrounding watershed (Brown and Krygier, 1970; Beschta et al., 1987; Chen et al., 1998; Poole and Berman, 2001). Coldwater fishes such as salmon and trout are sensitive to elevated water temperature...
Authors
R. N Handcock, Christian E. Torgersen, K. A Cherkauer, A. R Gillespie, K Tockner, R. N. Faux, Jing Tan
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Projected climate-induced habitat loss for salmonids in the John Day River network, Oregon, U.S.A. Projected climate-induced habitat loss for salmonids in the John Day River network, Oregon, U.S.A.

Climate change will likely have profound effects on cold-water species of freshwater fishes. As temperatures rise, cold-water fish distributions may shift and contract in response. Predicting the effects of projected stream warming in stream networks is complicated by the generally poor correlation between water temperature and air temperature. Spatial dependencies in stream networks are...
Authors
Aaron S. Ruesch, Christian E. Torgersen, Joshua J. Lawler, Julian D. Olden, Erin E. Peterson, Carol J. Volk, David J. Lawrence
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Non-USGS Publications**

Torgersen, C.E., Close, D.A., 2004, Influence of habitat heterogeneity on the distribution of larval Pacific lamprey (Lampetra tridentata) at two spatial scales: Freshwater Biology, v. 49, no. 5, p. 614-630.
Fausch, K.D., Torgersen, C.E., Baxter, C.V., Li, H.W., 2002, Landscapes to riverscapes- bridging the gap between research and conservation of stream fishes: BioScience, v. 52, no. 6, p. 483-498.
Torgersen, C.E., Faux, R.N., McIntosh, B.A., Poage, N., Norton, D.J., 2001, Airborne thermal remote sensing for water temperature assessment in rivers and streams: Remote Sensing of Environment, v. 76, p. 386-398.
Torgersen, C.E., Price, D.M., Li, H.W., McIntosh, B.A., 1999, Multiscale thermal refugia and stream habitat associations of chinook salmon in northwestern Oregon: Ecological Applications, v. 9, no. 1, p. 301-319, https://doi.org/10.1890/1051-0761(1999)009[0301:MTRASH]2.0.CO;2.
Torgersen, C.E., Poage, N., Flood, M., Norton, D.J., McIntosh, B.A., 1996, Airborne thermal remote sensing of salmonid habitat for restoration planning in Pacific Northwestern watersheds, Baltimore, MD In eds., Proceedings of the Watershed 96 Conference: Alexandria, VA, Water Environment Federation, p. 812-814.
Poage, N., Torgersen, C.E., Norton, D.J., Flood, M., McIntosh, B.A., 1996, Application of thermal infrared (FLIR) and visible videography to the monitoring and restoration of salmonid habitat in the Pacific Northwest In Greer, J.D., ed., Proceedings of the Sixth Forest Service Remote Sensing Applications Conference: Denver, CO, American Society for Photogrammetry and Remote Sensing, p. 376-379.
Torgersen, C.E., Jones, J.A., Moldenke, A.R., LeMaster, M.P., 1995, The spatial heterogeneity of soil invertebrates and edaphic properties in an old growth forest stand in western Oregon In Collins, H.P., Robertson, G.P., Klug, M.J., eds., The Significance and Regulation of Soil Biodiversity: Dordrecht, Netherlands, Kluwer Academic Publishers, p. 225-236.
Torgersen, C.E., Price, D.M., Li, H.W., McIntosh, B.A., 1995, Thermal refugia and chinook salmon habitat in Oregon- Applications of airborne thermal videography In Mausel, P., ed., Proceedings of the 15th Biennial Workshop on Color Photography and Videography: Terre Haute, IN, American Society for Photogrammetry and Remote Sensing, p. 167-171.
Torgersen, C.E., Baxter, C.V., Li, H., McIntosh, B.A., 2006, Landscape influences on longitudinal patterns of river fishes- Spatially continuous analysis of fish-habitat relationships In Hughes, R., Wang, L., Wofford, J.E., eds., Influences of Landscapes on Stream Habitats and Biological Assemblages: Bethesda, MD, American Fisheries Society, p. 473-492

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

To request an interview, contact fresc_outreach@usgs.gov or call (541) 750-1030.

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