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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

Envisioning, quantifying, and managing thermal regimes on river networks Envisioning, quantifying, and managing thermal regimes on river networks

Water temperatures fluctuate in time and space, creating diverse thermal regimes on river networks. Temporal variability in these thermal landscapes has important biological and ecological consequences because of nonlinearities in physiological reactions; spatial diversity in thermal landscapes provides aquatic organisms with options to maximize growth and survival. However, human...
Authors
E. Ashley Steel, Timothy J. Beechie, Christian E. Torgersen, Aimee H. Fullerton
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Status and trends of dam removal research in the United States Status and trends of dam removal research in the United States

Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been a proliferation of studies that assess the physical and ecological responses of rivers to these removals. As more dams are considered for removal, scientific information from these dam-removal studies will increasingly...
Authors
James Bellmore, Jeffrey J. Duda, Laura Craig, Samantha L. Greene, Christian E. Torgersen, Mathias J. Collins, Katherine Vittum
By
Ecosystems Mission Area, Species Management Research Program, Forest and Rangeland Ecosystem Science Center, John Wesley Powell Center for Analysis and Synthesis, Western Fisheries Research Center

Spatial variability of Chinook salmon spawning distribution and habitat preferences Spatial variability of Chinook salmon spawning distribution and habitat preferences

We investigated physical habitat conditions associated with the spawning sites of Chinook Salmon Oncorhynchus tshawytscha and the interannual consistency of spawning distribution across multiple spatial scales using a combination of spatially continuous and discrete sampling methods. We conducted a census of aquatic habitat in 76 km of the upper main-stem Yakima River in Washington and...
Authors
Jeremy M. Cram, Christian E. Torgersen, Ryan S. Klett, George R. Pess, Darran May, Todd N. Pearsons, Andrew H. Dittman
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Spatially intensive sampling by electrofishing for assessing longitudinal discontinuities in fish distribution in a headwater stream Spatially intensive sampling by electrofishing for assessing longitudinal discontinuities in fish distribution in a headwater stream

Spatially intensive sampling by electrofishing is proposed as a method for quantifying spatial variation in fish assemblages at multiple scales along extensive stream sections in headwater catchments. We used this method to sample fish species at 10-m2 points spaced every 20 m throughout 5 km of a headwater stream in France. The spatially intensive sampling design provided information at...
Authors
Celine Le Pichon, Evelyne Tales, Jerome Belliard, Christian E. Torgersen
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Dendritic network models: Improving isoscapes and quantifying influence of landscape and in-stream processes on strontium isotopes in rivers Dendritic network models: Improving isoscapes and quantifying influence of landscape and in-stream processes on strontium isotopes in rivers

A critical challenge for the Earth sciences is to trace the transport and flux of matter within and among aquatic, terrestrial, and atmospheric systems. Robust descriptions of isotopic patterns across space and time, called “isoscapes,” form the basis of a rapidly growing and wide-ranging body of research aimed at quantifying connectivity within and among Earth's systems. However...
Authors
Sean R. Brennan, Christian E. Torgersen, Jeff P. Hollenbeck, Diego P. Fernandez, Carrie K Jensen, Daniel E. Schindler
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Polymorphic mountain whitefish (Prosopium williamsoni) in a coastal riverscape: size class assemblages, distribution, and habitat associations Polymorphic mountain whitefish (Prosopium williamsoni) in a coastal riverscape: size class assemblages, distribution, and habitat associations

We compared the assemblage structure, spatial distributions, and habitat associations of mountain whitefish (Prosopium williamsoni) morphotypes and size classes. We hypothesised that morphotypes would have different spatial distributions and would be associated with different habitat features based on feeding behaviour and diet. Spatially continuous sampling was conducted over a broad...
Authors
James C. Starr, Christian E. Torgersen
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

Envisioning, quantifying, and managing thermal regimes on river networks Envisioning, quantifying, and managing thermal regimes on river networks

Water temperatures fluctuate in time and space, creating diverse thermal regimes on river networks. Temporal variability in these thermal landscapes has important biological and ecological consequences because of nonlinearities in physiological reactions; spatial diversity in thermal landscapes provides aquatic organisms with options to maximize growth and survival. However, human...
Authors
E. Ashley Steel, Timothy J. Beechie, Christian E. Torgersen, Aimee H. Fullerton
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Status and trends of dam removal research in the United States Status and trends of dam removal research in the United States

Aging infrastructure coupled with growing interest in river restoration has driven a dramatic increase in the practice of dam removal. With this increase, there has been a proliferation of studies that assess the physical and ecological responses of rivers to these removals. As more dams are considered for removal, scientific information from these dam-removal studies will increasingly...
Authors
James Bellmore, Jeffrey J. Duda, Laura Craig, Samantha L. Greene, Christian E. Torgersen, Mathias J. Collins, Katherine Vittum
By
Ecosystems Mission Area, Species Management Research Program, Forest and Rangeland Ecosystem Science Center, John Wesley Powell Center for Analysis and Synthesis, Western Fisheries Research Center

Spatial variability of Chinook salmon spawning distribution and habitat preferences Spatial variability of Chinook salmon spawning distribution and habitat preferences

We investigated physical habitat conditions associated with the spawning sites of Chinook Salmon Oncorhynchus tshawytscha and the interannual consistency of spawning distribution across multiple spatial scales using a combination of spatially continuous and discrete sampling methods. We conducted a census of aquatic habitat in 76 km of the upper main-stem Yakima River in Washington and...
Authors
Jeremy M. Cram, Christian E. Torgersen, Ryan S. Klett, George R. Pess, Darran May, Todd N. Pearsons, Andrew H. Dittman
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Spatially intensive sampling by electrofishing for assessing longitudinal discontinuities in fish distribution in a headwater stream Spatially intensive sampling by electrofishing for assessing longitudinal discontinuities in fish distribution in a headwater stream

Spatially intensive sampling by electrofishing is proposed as a method for quantifying spatial variation in fish assemblages at multiple scales along extensive stream sections in headwater catchments. We used this method to sample fish species at 10-m2 points spaced every 20 m throughout 5 km of a headwater stream in France. The spatially intensive sampling design provided information at...
Authors
Celine Le Pichon, Evelyne Tales, Jerome Belliard, Christian E. Torgersen
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Dendritic network models: Improving isoscapes and quantifying influence of landscape and in-stream processes on strontium isotopes in rivers Dendritic network models: Improving isoscapes and quantifying influence of landscape and in-stream processes on strontium isotopes in rivers

A critical challenge for the Earth sciences is to trace the transport and flux of matter within and among aquatic, terrestrial, and atmospheric systems. Robust descriptions of isotopic patterns across space and time, called “isoscapes,” form the basis of a rapidly growing and wide-ranging body of research aimed at quantifying connectivity within and among Earth's systems. However...
Authors
Sean R. Brennan, Christian E. Torgersen, Jeff P. Hollenbeck, Diego P. Fernandez, Carrie K Jensen, Daniel E. Schindler
By
Ecosystems Mission Area, Forest and Rangeland Ecosystem Science Center

Polymorphic mountain whitefish (Prosopium williamsoni) in a coastal riverscape: size class assemblages, distribution, and habitat associations Polymorphic mountain whitefish (Prosopium williamsoni) in a coastal riverscape: size class assemblages, distribution, and habitat associations

We compared the assemblage structure, spatial distributions, and habitat associations of mountain whitefish (Prosopium williamsoni) morphotypes and size classes. We hypothesised that morphotypes would have different spatial distributions and would be associated with different habitat features based on feeding behaviour and diet. Spatially continuous sampling was conducted over a broad...
Authors
James C. Starr, Christian E. Torgersen
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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