Theodore Kennedy, Ph.D.
I use food webs to describe ecosystem response to river regulation and biological invasions. I have been with USGS since 2004, providing science in support of the Glen Canyon Dam Adaptive Management Program.
Professional Experience
11/04 - present: Research Ecologist, Grand Canyon Monitoring and Research Center, Southwest Biological Science Center, US Geological Survey, Flagstaff, AZ
1/04 - 11/04: Postdoctoral researcher, Arizona State University
1/03 - 1/04: Postdoctoral researcher, Grand Canyon Monitoring and Research Center, Southwest Biological Science Center, US Geological Survey, Flagstaff, AZ.
Education and Certifications
9/96 - 12/02: Ph.D. in Ecology, Dept. of Ecology, Evolution, and Behavior, University of Minnesota. Dissertation title: The causes and consequences of plant invasions
1/90 - 12/94: B.S. in Ecology, California Polytechnic State University at San Luis Obispo, cum laude.
Science and Products
Filter Total Items: 15
No Result Found
Filter Total Items: 63
Abiotic & biotic responses of the Colorado River to controlled floods at Glen Canyon Dam, Arizona, USA Abiotic & biotic responses of the Colorado River to controlled floods at Glen Canyon Dam, Arizona, USA
Closure of Glen Canyon Dam reduced sand supply to the Colorado River in Grand Canyon National Park by about 94% while its operation has also eroded the park's sandbar habitats. Three controlled floods released from the dam since 1995 suggest that sandbars might be rebuilt and maintained, but only if repeated floods are timed to follow tributary sand deliveries below the dam. Monitoring...
Authors
Josh Korman, Ted Melis, Theodore A. Kennedy
Air-water oxygen exchange in a large whitewater river Air-water oxygen exchange in a large whitewater river
Air–water gas exchange governs fluxes of gas into and out of aquatic ecosystems. Knowing this flux is necessary to calculate gas budgets (i.e., O2) to estimate whole‐ecosystem metabolism and basin‐scale carbon budgets. Empirical data on rates of gas exchange for streams, estuaries, and oceans are readily available. However, there are few data from large rivers and no data from whitewater...
Authors
Robert O. Hall, Theodore A. Kennedy, Emma Rosi-Marshall
Regulation leads to increases in riparian vegetation, but not direct allochthonous inputs, along the Colorado River in Grand Canyon, Arizona Regulation leads to increases in riparian vegetation, but not direct allochthonous inputs, along the Colorado River in Grand Canyon, Arizona
Dams and associated river regulation have led to the expansion of riparian vegetation, especially nonnative species, along downstream ecosystems. Nonnative saltcedar is one of the dominant riparian plants along virtually every major river system in the arid western United States, but allochthonous inputs have never been quantified along a segment of a large river that is dominated by...
Authors
T.A. Kennedy, B.E. Ralston
Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon
Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high‐flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, USA, in an effort to reestablish pulsed...
Authors
Wyatt Cross, Colden V. Baxter, Kevin Donner, Emma Rosi-Marshall, Theodore A. Kennedy, Robert O. Hall, Holly Wellard Kelly, R. Scott Rogers
Effects of three high-flow experiments on the Colorado River ecosystem downstream from Glen Canyon Dam, Arizona Effects of three high-flow experiments on the Colorado River ecosystem downstream from Glen Canyon Dam, Arizona
Three high-flow experiments (HFEs) were conducted by the U.S. Department of the Interior at Glen Canyon Dam, Arizona, in March 1996, November 2004, and March 2008. These experiments, also known as artificial or controlled floods, were large-volume, scheduled releases of water from Glen Canyon Dam that were designed to mimic some aspects of pre-dam Colorado River seasonal flooding. The...
Authors
Theodore S. Melis
Three experimental high-flow releases from Glen Canyon Dam, Arizona— Effects on the downstream Colorado River ecosystem Three experimental high-flow releases from Glen Canyon Dam, Arizona— Effects on the downstream Colorado River ecosystem
Three high-flow experiments (HFEs) were conducted by the U.S. Department of the Interior at Glen Canyon Dam, Arizona, in March 1996, November 2004, and March 2008. Also known as artificial or controlled floods, these scheduled releases of water above the dam's powerplant capacity were designed to mimic pre-dam seasonal flooding on the Colorado River. The goal of the HFEs was to determine...
Authors
Theodore S. Melis, Paul Grams, Theodore A. Kennedy, Barbara E. Ralston, Christopher Robinson, John Schmidt, Lara Schmit, Richard A. Valdez, Scott Wright
Proceedings of the Colorado River Basin Science and Resource Management Symposium, November 18-20, 2008, Scottsdale, Arizona Proceedings of the Colorado River Basin Science and Resource Management Symposium, November 18-20, 2008, Scottsdale, Arizona
Since the 1980s, four major science and restoration programs have been developed for the Colorado River Basin to address primarily the conservation of native fish and other wildlife pursuant to the Endangered Species Act (ESA): (1) Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin (commonly called the Upper Colorado River Endangered Fish...
Authors
Theodore S. Melis, John Hamill, Glenn E. Bennett, Coggins, Paul Grams, Theodore A. Kennedy, Dennis Kubly, Barbara E. Ralston
Basal Resources in Backwaters of the Colorado River Below Glen Canyon Dam-Effects of Discharge Regimes and Comparison with Mainstem Depositional Environments Basal Resources in Backwaters of the Colorado River Below Glen Canyon Dam-Effects of Discharge Regimes and Comparison with Mainstem Depositional Environments
Eight species of fish were native to the Colorado River before the closure of Glen Canyon Dam, but only four of these native species are currently present. A variety of factors are responsible for the loss of native fish species and the limited distribution and abundance of those that remain. These factors include cold and constant water temperatures, predation and competition with...
Authors
Katherine Behn, Theodore A. Kennedy, Robert O. Hall
Short-Term Effects of the 2008 High-Flow Experiment on Macroinvertebrates in Colorado River Below Glen Canyon Dam, Arizona Short-Term Effects of the 2008 High-Flow Experiment on Macroinvertebrates in Colorado River Below Glen Canyon Dam, Arizona
Glen Canyon Dam has dramatically altered the physical environment (especially discharge regime, water temperatures, and sediment inputs) of the Colorado River. High-flow experiments (HFE) that mimic one aspect of the natural hydrograph (floods) were implemented in 1996, 2004, and 2008. The primary goal of these experiments was to increase the size and total area of sandbar habitats that...
Authors
Emma Rosi-Marshall, Theodore A. Kennedy, Dustin W. Kincaid, Wyatt Cross, Holly Kelly, Kathrine A. Behn, Tyler White, Robert O. Hall, Colden V. Baxter
2008 High-Flow Experiment at Glen Canyon Dam Benefits Colorado River Resources in Grand Canyon National Park 2008 High-Flow Experiment at Glen Canyon Dam Benefits Colorado River Resources in Grand Canyon National Park
On March 5, 2008, the Department of the Interior began a 60-hour high-flow experiment at Glen Canyon Dam, Arizona, to determine if water releases designed to mimic natural seasonal flooding could be used to improve downstream resources in Glen Canyon National Recreation Area and Grand Canyon National Park. U.S. Geological Survey (USGS) scientists and their cooperators undertook a wide...
Authors
Theodore S. Melis, David Topping, Paul Grams, David Rubin, Scott Wright, Amy Draut, Joseph E. Hazel, Barbara E. Ralston, Theodore A. Kennedy, Emma Rosi-Marshall, Josh Korman, Kara Hilwig, Lara Schmit
Invasion and production of New Zealand mud snails in the Colorado River, Glen Canyon Invasion and production of New Zealand mud snails in the Colorado River, Glen Canyon
Species invasions are often associated with large-scale human alteration of ecosystems. One classic example is the increasing dominance of non-native taxa below and above dams on large rivers. These dams substantially alter the physical template of river ecosystems, and exotic taxa often proliferate with potentially large impacts on coexisting taxa and ecosystem processes. Here we...
Authors
Wyatt Cross, E.J. Rosi-Marshall, Katherine Behn, Theodore Kennedy, Robert Hall, A. Fuller, C. Baxter
The role of discharge variation in scaling of drainage area and food chain length in rivers The role of discharge variation in scaling of drainage area and food chain length in rivers
Food chain length (FCL) is a fundamental component of food web structure. Studies in a variety of ecosystems suggest that FCL is determined by energy supply, environmental stability, and/or ecosystem size, but the nature of the relationship between environmental stability and FCL, and the mechanism linking ecosystem size to FCL, remain unclear. Here we show that FCL increases with...
Authors
John Sabo, Jacques Finlay, Theodore A. Kennedy, David M. Post
Non-USGS Publications**
Kennedy, T.A., 1998, Patterns of an invasion by Argentine ants (Linepithema humile) in a riparian corridor and its effects on ant diversity: The American Midland Naturalist, v. 140, p. 343-350.
Naeem, S., Knops, J.M., Tilman, D., Howe, K.M., Kennedy, T. and Gale, S., 2000, Plant diversity increases resistance to invasion in the absence of covarying extrinsic factors: Oikos, v. 91, p. 97-108, DOI: 10.1034/j.1600-0706.2000.910108.x.
Raffaelli, D., Van der Putten, W.H., Persson, L., Wardle, D.A., Petchey, O.L., Koricheva, J., Van Der Heijden, M., Mikola, J. and Kennedy, T., 2002, Multi-trophic dynamics and ecosystem processes, In Loreau, M., Naeem, S., and Inchausti, P., eds., Biodiversity and ecosystem functioning: synthesis and perspectives: Oxford, Oxford University Press, p.147-154.
Levine, J.M., Kennedy, T., and Naeem, S., 2002, Neighborhood scale effects of species diversity on biological invasions and their relationship to community patterns, In Loreau, M., Naeem, S., and Inchausti, P., eds., Biodiversity and ecosystem functioning: synthesis and perspectives: Oxford, Oxford University Press, p.114-124.
Kennedy, T.A., Naeem, S., Howe, K.M., Knops, J.M., Tilman, D., and Reich, P., 2002, Biodiversity as a barrier to ecological invasion. Nature, v.417, p.636. doi:10.1038/nature00776.
Kennedy, T.A., and Hobbie, S.E., 2004, Saltcedar (Tamarix ramosissima) invasion alters organic matter dynamics in a desert stream. Freshwater Biology, v. 49, p. 65-76. doi: 10.1046/j.1365-2426.2003.01166.x.
Kennedy, T.A., Finlay, J.C., and Hobbie, S.E., 2005, Eradication of invasive Tamarix ramosissima along a desert stream increases native fish density: Ecological Applications, v. 15, p. 2072-2083.
**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.
Science and Products
Filter Total Items: 15
No Result Found
Filter Total Items: 63
Abiotic & biotic responses of the Colorado River to controlled floods at Glen Canyon Dam, Arizona, USA Abiotic & biotic responses of the Colorado River to controlled floods at Glen Canyon Dam, Arizona, USA
Closure of Glen Canyon Dam reduced sand supply to the Colorado River in Grand Canyon National Park by about 94% while its operation has also eroded the park's sandbar habitats. Three controlled floods released from the dam since 1995 suggest that sandbars might be rebuilt and maintained, but only if repeated floods are timed to follow tributary sand deliveries below the dam. Monitoring...
Authors
Josh Korman, Ted Melis, Theodore A. Kennedy
Air-water oxygen exchange in a large whitewater river Air-water oxygen exchange in a large whitewater river
Air–water gas exchange governs fluxes of gas into and out of aquatic ecosystems. Knowing this flux is necessary to calculate gas budgets (i.e., O2) to estimate whole‐ecosystem metabolism and basin‐scale carbon budgets. Empirical data on rates of gas exchange for streams, estuaries, and oceans are readily available. However, there are few data from large rivers and no data from whitewater...
Authors
Robert O. Hall, Theodore A. Kennedy, Emma Rosi-Marshall
Regulation leads to increases in riparian vegetation, but not direct allochthonous inputs, along the Colorado River in Grand Canyon, Arizona Regulation leads to increases in riparian vegetation, but not direct allochthonous inputs, along the Colorado River in Grand Canyon, Arizona
Dams and associated river regulation have led to the expansion of riparian vegetation, especially nonnative species, along downstream ecosystems. Nonnative saltcedar is one of the dominant riparian plants along virtually every major river system in the arid western United States, but allochthonous inputs have never been quantified along a segment of a large river that is dominated by...
Authors
T.A. Kennedy, B.E. Ralston
Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon Ecosystem ecology meets adaptive management: food web response to a controlled flood on the Colorado River, Glen Canyon
Large dams have been constructed on rivers to meet human demands for water, electricity, navigation, and recreation. As a consequence, flow and temperature regimes have been altered, strongly affecting river food webs and ecosystem processes. Experimental high‐flow dam releases, i.e., controlled floods, have been implemented on the Colorado River, USA, in an effort to reestablish pulsed...
Authors
Wyatt Cross, Colden V. Baxter, Kevin Donner, Emma Rosi-Marshall, Theodore A. Kennedy, Robert O. Hall, Holly Wellard Kelly, R. Scott Rogers
Effects of three high-flow experiments on the Colorado River ecosystem downstream from Glen Canyon Dam, Arizona Effects of three high-flow experiments on the Colorado River ecosystem downstream from Glen Canyon Dam, Arizona
Three high-flow experiments (HFEs) were conducted by the U.S. Department of the Interior at Glen Canyon Dam, Arizona, in March 1996, November 2004, and March 2008. These experiments, also known as artificial or controlled floods, were large-volume, scheduled releases of water from Glen Canyon Dam that were designed to mimic some aspects of pre-dam Colorado River seasonal flooding. The...
Authors
Theodore S. Melis
Three experimental high-flow releases from Glen Canyon Dam, Arizona— Effects on the downstream Colorado River ecosystem Three experimental high-flow releases from Glen Canyon Dam, Arizona— Effects on the downstream Colorado River ecosystem
Three high-flow experiments (HFEs) were conducted by the U.S. Department of the Interior at Glen Canyon Dam, Arizona, in March 1996, November 2004, and March 2008. Also known as artificial or controlled floods, these scheduled releases of water above the dam's powerplant capacity were designed to mimic pre-dam seasonal flooding on the Colorado River. The goal of the HFEs was to determine...
Authors
Theodore S. Melis, Paul Grams, Theodore A. Kennedy, Barbara E. Ralston, Christopher Robinson, John Schmidt, Lara Schmit, Richard A. Valdez, Scott Wright
Proceedings of the Colorado River Basin Science and Resource Management Symposium, November 18-20, 2008, Scottsdale, Arizona Proceedings of the Colorado River Basin Science and Resource Management Symposium, November 18-20, 2008, Scottsdale, Arizona
Since the 1980s, four major science and restoration programs have been developed for the Colorado River Basin to address primarily the conservation of native fish and other wildlife pursuant to the Endangered Species Act (ESA): (1) Recovery Implementation Program for Endangered Fish Species in the Upper Colorado River Basin (commonly called the Upper Colorado River Endangered Fish...
Authors
Theodore S. Melis, John Hamill, Glenn E. Bennett, Coggins, Paul Grams, Theodore A. Kennedy, Dennis Kubly, Barbara E. Ralston
Basal Resources in Backwaters of the Colorado River Below Glen Canyon Dam-Effects of Discharge Regimes and Comparison with Mainstem Depositional Environments Basal Resources in Backwaters of the Colorado River Below Glen Canyon Dam-Effects of Discharge Regimes and Comparison with Mainstem Depositional Environments
Eight species of fish were native to the Colorado River before the closure of Glen Canyon Dam, but only four of these native species are currently present. A variety of factors are responsible for the loss of native fish species and the limited distribution and abundance of those that remain. These factors include cold and constant water temperatures, predation and competition with...
Authors
Katherine Behn, Theodore A. Kennedy, Robert O. Hall
Short-Term Effects of the 2008 High-Flow Experiment on Macroinvertebrates in Colorado River Below Glen Canyon Dam, Arizona Short-Term Effects of the 2008 High-Flow Experiment on Macroinvertebrates in Colorado River Below Glen Canyon Dam, Arizona
Glen Canyon Dam has dramatically altered the physical environment (especially discharge regime, water temperatures, and sediment inputs) of the Colorado River. High-flow experiments (HFE) that mimic one aspect of the natural hydrograph (floods) were implemented in 1996, 2004, and 2008. The primary goal of these experiments was to increase the size and total area of sandbar habitats that...
Authors
Emma Rosi-Marshall, Theodore A. Kennedy, Dustin W. Kincaid, Wyatt Cross, Holly Kelly, Kathrine A. Behn, Tyler White, Robert O. Hall, Colden V. Baxter
2008 High-Flow Experiment at Glen Canyon Dam Benefits Colorado River Resources in Grand Canyon National Park 2008 High-Flow Experiment at Glen Canyon Dam Benefits Colorado River Resources in Grand Canyon National Park
On March 5, 2008, the Department of the Interior began a 60-hour high-flow experiment at Glen Canyon Dam, Arizona, to determine if water releases designed to mimic natural seasonal flooding could be used to improve downstream resources in Glen Canyon National Recreation Area and Grand Canyon National Park. U.S. Geological Survey (USGS) scientists and their cooperators undertook a wide...
Authors
Theodore S. Melis, David Topping, Paul Grams, David Rubin, Scott Wright, Amy Draut, Joseph E. Hazel, Barbara E. Ralston, Theodore A. Kennedy, Emma Rosi-Marshall, Josh Korman, Kara Hilwig, Lara Schmit
Invasion and production of New Zealand mud snails in the Colorado River, Glen Canyon Invasion and production of New Zealand mud snails in the Colorado River, Glen Canyon
Species invasions are often associated with large-scale human alteration of ecosystems. One classic example is the increasing dominance of non-native taxa below and above dams on large rivers. These dams substantially alter the physical template of river ecosystems, and exotic taxa often proliferate with potentially large impacts on coexisting taxa and ecosystem processes. Here we...
Authors
Wyatt Cross, E.J. Rosi-Marshall, Katherine Behn, Theodore Kennedy, Robert Hall, A. Fuller, C. Baxter
The role of discharge variation in scaling of drainage area and food chain length in rivers The role of discharge variation in scaling of drainage area and food chain length in rivers
Food chain length (FCL) is a fundamental component of food web structure. Studies in a variety of ecosystems suggest that FCL is determined by energy supply, environmental stability, and/or ecosystem size, but the nature of the relationship between environmental stability and FCL, and the mechanism linking ecosystem size to FCL, remain unclear. Here we show that FCL increases with...
Authors
John Sabo, Jacques Finlay, Theodore A. Kennedy, David M. Post
Non-USGS Publications**
Kennedy, T.A., 1998, Patterns of an invasion by Argentine ants (Linepithema humile) in a riparian corridor and its effects on ant diversity: The American Midland Naturalist, v. 140, p. 343-350.
Naeem, S., Knops, J.M., Tilman, D., Howe, K.M., Kennedy, T. and Gale, S., 2000, Plant diversity increases resistance to invasion in the absence of covarying extrinsic factors: Oikos, v. 91, p. 97-108, DOI: 10.1034/j.1600-0706.2000.910108.x.
Raffaelli, D., Van der Putten, W.H., Persson, L., Wardle, D.A., Petchey, O.L., Koricheva, J., Van Der Heijden, M., Mikola, J. and Kennedy, T., 2002, Multi-trophic dynamics and ecosystem processes, In Loreau, M., Naeem, S., and Inchausti, P., eds., Biodiversity and ecosystem functioning: synthesis and perspectives: Oxford, Oxford University Press, p.147-154.
Levine, J.M., Kennedy, T., and Naeem, S., 2002, Neighborhood scale effects of species diversity on biological invasions and their relationship to community patterns, In Loreau, M., Naeem, S., and Inchausti, P., eds., Biodiversity and ecosystem functioning: synthesis and perspectives: Oxford, Oxford University Press, p.114-124.
Kennedy, T.A., Naeem, S., Howe, K.M., Knops, J.M., Tilman, D., and Reich, P., 2002, Biodiversity as a barrier to ecological invasion. Nature, v.417, p.636. doi:10.1038/nature00776.
Kennedy, T.A., and Hobbie, S.E., 2004, Saltcedar (Tamarix ramosissima) invasion alters organic matter dynamics in a desert stream. Freshwater Biology, v. 49, p. 65-76. doi: 10.1046/j.1365-2426.2003.01166.x.
Kennedy, T.A., Finlay, J.C., and Hobbie, S.E., 2005, Eradication of invasive Tamarix ramosissima along a desert stream increases native fish density: Ecological Applications, v. 15, p. 2072-2083.
**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.