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Emergency Management

Patrick Shafroth, Ph.D.

Biography

Patrick B. Shafroth is a research ecologist with the U.S. Geological Survey, Fort Collins Science Center. Since 1991, Dr. Shafroth has conducted research on riparian ecosystems, primarily in arid and semi-arid regions of western U.S. He and his colleagues from the USGS and other institutions have focused their work on understanding relationships between surface and ground-water hydrology, fluvial processes, and the dynamics of native and introduced riparian vegetation. This research has often been conducted in the applied context of riparian ecosystem restoration with the goal of providing solid, objective scientific information that can be used to inform riparian restoration efforts. More specific restoration-related research areas include studies of large-scale flow experiments, dam removal, effects of invasive species control and associated restoration actions, and potential interactions with climate change.

Some of Dr. Shafroth’s current research includes studies of: vegetation and geomorphic responses to experimental flow releases downstream of dams on the Bill Williams River, Arizona; the Colorado River delta in Mexico and the U.S.; and the the Colorado River in Grand Canyon; vegetation and geomorphic responses to dam removal on the Elwha River, Washington, where the world's largest dam removals occurred recently; dynamics of non-native riparian plants along western rivers, including patterns of riparian vegetation recovery associated with biological control of Tamarix.

Education

  • Ph.D. in Plant Biology, Arizona State University, 1999
  • M.S. in Forest Ecology, Colorado State University, 1993
  • B.A. in Environmental Studies and Geography, University of California, Santa Barbara, 1989

Science and Products

Filter Total Items: 6
Erosion along the Rio Puerco during the flood of 2006 following herbicide application to control saltcedar in 2003.
Date published: December 3, 2016

Erosion and Invasive Saltcedar

Formation of arroyos in the late 1800s greatly increased erosion across the southwestern United States. Since the 1930s, however, this erosion has decreased, partly because of bank stabilization by introduced saltcedar. With Isleta Pueblo Indian Nation, the Aquatic Systems Branch developed a new sediment dating method using saltcedar tree rings. We applied the method in a landmark study of...

Contacts: Jonathan Friedman, Ph.D., Gregor Auble, Ph.D., Patrick Shafroth, Ph.D., Eleanor Griffin
Attribution: Ecosystems, Water Resources, Environments Program, Invasive Species Program, Water Availability and Use Science Program, Southwest, Fort Collins Science Center
Glines Canyon Dam on the Elwha River, during the dam removal process. Photo credit: National Park Service
Date published: November 29, 2016

Riparian Vegetation Response to Dam Removal

Dam removal is an approach to river restoration that is becoming increasingly common. In most cases, dam removal is driven by considerations other than river restoration like dam safety, but how dam removal affects aquatic and riparian systems is of great interest in many dam removals. My work in this area has had two areas of focus thus far: 1) studies of vegetation and geomorphic change...

Contacts: Patrick Shafroth, Ph.D.
Attribution: Ecosystems, Coastal and Marine Geology, Environments Program, Northwest, Southwest, Fort Collins Science Center
The South Platte River. USGS Water Science Center image.
Date published: November 29, 2016

Science to Inform Riparian Ecosystem Restoration and Management

Throughout the world, riparian habitats have been dramatically modified from their natural condition. Dams, non-native species and climate change are often principal drivers of these changes, via their alteration of water and sediment regimes that determine key resources for riparian plants.

Contacts: Patrick Shafroth, Ph.D.
Attribution: Ecosystems, Environments Program, Invasive Species Program, Southwest, Fort Collins Science Center
The Bill Williams River in Arizona. USGS photo.
Date published: November 29, 2016

Large-scale streamflow experiments

Because the underlying cause of riparian system alteration is often attributed to the effects of dams on flow regime, managing flow releases, particularly high flows, from dams is an often-advocated approach to river and riparian restoration. Our work has focused on understanding effects of managed high flow releases (a.k.a., pulse flows, controlled floods) from dams along rivers in the lower...

Contacts: Patrick Shafroth, Ph.D.
Attribution: Ecosystems, Environments Program, Invasive Species Program, Southwest, Fort Collins Science Center
Extensive defoliation of tamarisk (orange/brown vegetation throughout mid-ground) along the Virgin River, Arizona, 2009.
Date published: November 28, 2016

Biological Invasions of Riparian Ecosystems

Beginning in the early twentieth century, non-native trees and shrubs, including tamarisk (also commonly known as saltcedar) and Russian-olive, were introduced to the United States for use as ornamental plants and in erosion-control plantings. These plants spread extensively, becoming the third and fourth most frequently occurring woody riparian plants in the American West.

 

Contacts: Patrick Shafroth, Ph.D.
Attribution: Ecosystems, Environments Program, Invasive Species Program, Southwest, Fort Collins Science Center
The unregulated Santa Maria River in west-central Arizona.
Date published: November 28, 2016

Streamflow-fluvial Geomorphology-riparian Vegetation Interactions

The foundation for applying science to river and riparian restoration contexts lies in a basic understanding of the factors that drive riparian vegetation dynamics. Much of our research is focused on clarifying relationships between streamflow, fluvial geomorphology, and riparian vegetation, including various feedbacks.

Contacts: Patrick Shafroth, Ph.D.
Attribution: Ecosystems, Environments Program, Invasive Species Program, Southwest, Fort Collins Science Center
Filter Total Items: 95
Year Published: 2018

Regeneration of Salicaceae riparian forests in the Northern Hemisphere: A new framework and management tool

Human activities on floodplains have severely disrupted the regeneration of foundation riparian shrub and tree species of the Salicaceae family (Populus and Salix spp.) throughout the Northern Hemisphere. Restoration ecologists initially tackled this problem from a terrestrial perspective that emphasized planting....

Gonzalez, Eduardo; Martinez-Fernandez, Vanesa; Shafroth, Patrick B.; Sher, Anna A.; Henry, Annie L.; Garofano-Gomez, Virginia; Corenblit, Dov
View Citation
Gonzalez, E., V. Martinez-Fernandez, P.B. Shafroth, A.A. Sher, A.L. Henry, V. Garofano-Gomez, and D. Corenblit. 2018. Regeneration of Salicaceae riparian forests in the Northern Hemisphere: a new framework and management tool. Journal of Environmental Management 218:374-387.

Year Published: 2018

Landscape-scale processes influence riparian plant composition along a regulated river

Hierarchical frameworks are useful constructs when exploring landscape- and local-scale factors affecting patterns of vegetation in riparian areas. In drylands, which have steep environmental gradients and high habitat heterogeneity, landscape-scale variables, such as climate, can change rapidly along a river's course, affecting the relative...

Palmquist, Emily C.; Ralston, Barbara; Merritt, David M.; Shafroth, Patrick B.
View Citation
Palmquist, E.C., Ralston, B.E., Merritt, D.M., and Shafroth, P.B., 2017, in press, Landscape-scale processes influence riparian plant composition along a regulated river: Journal of Arid Environments, v. (online), https://doi.org/10.1016/j.jaridenv.2017.10.001.

Year Published: 2017

Effectiveness of environmental flows for riparian restoration in arid regions: A tale of four rivers

Environmental flows have become important restoration tools on regulated rivers. However, environmental flows are often constrained by other demands within the river system and thus typically are comprised of smaller water volumes than the natural flows they are meant to replace, which can limit their functional efficacy. We review...

Glenn, Edward P.; Nagler, Pamela L.; Shafroth, Patrick B.; Jarchow, Christopher
View Citation
Glenn, E.P., Nagler, P.L., Shafroth, P.B., and Jarchow, C.J., 2017, Effectiveness of environmental flows for riparian restoration in arid regions--A tale of four rivers: Ecological Engineering, v. 106, part B, p. 695-703, https://doi.org/10.1016/j.ecoleng.2017.01.009.

Year Published: 2017

Riparian plant composition along hydrologic gradients in a dryland river basin and implications for a warming climate

Droughts in dryland regions on all continents are expected to increase in severity and duration under future climate projections. In dryland regions, it is likely that minimum streamflow will decrease with some perennial streams shifting to intermittent flow under climate-driven changes in precipitation and runoff and increases in temperature....

Reynolds, Lindsay; Shafroth, Patrick B.
View Citation
Reynolds, L.V. and P.B. Shafroth. Riparian plant composition along hydrologic gradients in a dryland river basin and implications for a warming climate. Ecohydrology 10:e1864.

Year Published: 2017

Secondary invasions of noxious weeds associated with control of invasive Tamarix are frequent, idiosyncratic and persistent

Control of invasive species within ecosystems may induce secondary invasions of non-target invaders replacing the first alien. We used four plant species listed as noxious by local authorities in riparian systems to discern whether 1) the severity of these secondary invasions was related to the control method applied to the first alien; and 2)...

González, Eduardo; Sher, Anna A.; Anderson, Robert M.; Bay, Robin F.; Bean, Daniel W.; Bissonnete, Gabriel J.; Cooper, David J.; Dohrenwend, Kara; Eichhorst, Kim D.; El Waer, Hisham; Kennard, Deborah K.; Harms-Weissinger, Rebecca; Henry, Annie L.; Makarick, Lori J.; Ostoja, Steven M.; Reynolds, Lindsay V.; Robinson, W. Wright; Shafroth, Patrick B.; Tabacchi, Erich
View Citation
Gonzalez, E., A.A. Sher, R.M. Anderson, R.F. Bay, D.W. Bean, G.J. Bissonnete, D.J. Cooper, K. Dohrenwend, K.D. Eichhorst, H. El Waer, D.K. Kennard, R. Harms-Weissinger, A.L. Henry, L.J. Makarick, S.M. Ostoja, L.V. Reynolds, W.W. Robinson, P.B. Shafroth, and E. Tabacchi. 2017. Secondary invasions of noxious weeds associated with control of invasive Tamarix are frequent, idiosyncratic and persistent. Biological Conservation 213:106-114.

Year Published: 2017

Vegetation response to invasive Tamarix control in southwestern U.S. rivers: A collaborative study including 416 sites

Most studies assessing vegetation response following control of invasive Tamarix trees along southwestern U.S. rivers have been small in scale (e.g., river reach), or at a regional scale but with poor spatial-temporal replication, and most have not included testing the effects of a now widely used biological control. We monitored plant...

González, Eduardo; Sher, Anna A; Anderson, Robert M.; Bay, Robin F.; Bean, Daniel W.; Bissonnete, Gabriel J.; Bourgeois, Bérenger; Cooper, David J.; Dohrenwend, Kara; Eichhorst, Kim D.; El Waer, Hisham; Kennard, Deborah K.; Harms-Weissinger, Rebecca; Henry, Annie L.; Makarick, Lori J.; Ostoja, Steven M.; Reynolds, Lindsay V.; Robinson, W. Wright; Shafroth, Patrick B.
View Citation
Gonzalez, E., A.A. Sher, R.M. Anderson, R.F. Bay, D.W. Bean, G.J. Bissonnete, B. Bourgeois, D.J. Cooper, K. Dohrenwend, K.D. Eichhorst, H. El Waer, D.K. Kennard, R. Harms-Weissinger, A.L. Henry, L.J. Makarick, S.M. Ostoja, L.V. Reynolds, W.W. Robinson, and P.B. Shafroth. Vegetation response to control of invasive Tamarix in southwestern U.S. rivers: a collaborative study including 416 sites. Ecological Applications 27:1789-1804.

Year Published: 2017

A large-scale environmental flow experiment for riparian restoration in the Colorado River delta

Managing streamflow is a widely-advocated approach to provide conditions necessary for seed germination and seedling establishment of trees in the willow family (Salicaceae). Experimental flow releases to the Colorado River delta in 2014 had a primary objective of promoting seedling establishment of Fremont cottonwood (Populus fremontii) and...

Shafroth, Patrick B.; Schlatter, Karen; Gomez-Sapiens, Martha; Lundgren, Erick; Grabau, Matthew R. ; Ramirez-Hernandez, Jorge; Rodriguez-Burgeueno, J. Eliana; Flessa, Karl W.

Year Published: 2017

Integrating active restoration with environmental flows to improve native riparian tree establishment in the Colorado River Delta

Drastic alterations to river hydrology, land use change, and the spread of the nonnative shrub, tamarisk (Tamarix spp.), have led to the degradation of riparian habitat in the Colorado River Delta in Mexico. Delivery of environmental flows to promote native cottonwood (Populus spp.) and willow (Salix spp.) recruitment in human-impacted riparian...

Schlatter, Karen; Grabau, Matthew R. ; Shafroth, Patrick B.; Zamora-Arroyo, Francisco
View Citation
Schlatter, K.J., M.R. Grabau, P.B. Shafroth, and F. Zamora-Arroyo. 2017. Integrating active restoration with environmental flows to improve native riparian tree establishment in the Colorado River delta. Ecological Engineering 106:661-674.

Year Published: 2017

Dam removal: Listening in

Dam removal is widely used as an approach for river restoration in the United States. The increase in dam removals—particularly large dams—and associated dam-removal studies over the last few decades motivated a working group at the USGS John Wesley Powell Center for Analysis and Synthesis to review and synthesize available studies of dam removals...

Foley, Melissa M.; Bellmore, James; O'Connor, James E.; Duda, Jeff; East, Amy E.; Grant, Gordon G.; Anderson, Chauncey; Bountry, Jennifer A.; Collins, Mathias J.; Connolly, Patrick J.; Craig, Laura S.; Evans, James E.; Greene, Samantha; Magilligan, Francis J.; Magirl, Christopher S.; Major, Jon J.; Pess, George R.; Randle, Timothy J.; Shafroth, Patrick B.; Torgersen, Christian E.; Tullos, Desiree D.; Wilcox, Andrew C.
View Citation
Foley, M.M., Bellmore, J.R., O'Connor, J.E., Duda, J.J., East, A.E., Grant, G.E., Anderson, C.W., Bountry, J.A., Collins, M.J., Connolly, P.J., Craig, L.S., Evans, J.E., Greene, S.L., Magilligan, F.J., Magirl, C.S., Major, J.J., Pess, G.R., Randle, T.J., Shafroth, P.B., Torgersen, C.E., Tullos, D., Wilcox, A.C. and Powell Center Dam Removal Working Group, available online 2017, Dam removal—listening in: Water Resources Research, doi:10.1002/2017WR020457

Year Published: 2017

It takes more than water: Restoring the Colorado River Delta

Environmental flows have become important tools for restoring rivers and associated riparian ecosystems (Arthington, 2012; Glenn et al., 2017). In March 2014, the United States and Mexico initiated a bold effort in restoration, delivering from Morelos Dam a “pulse flow” of water into the Colorado River in its delta for the purpose of learning...

Pitt, Jennifer; Kendy, Eloise; Schlatter, Karen; Hinojosa-Huertaf, Osvel; Flessa, Karl W.; Shafroth, Patrick B.; Ramirez-Hernandez, Jorge; Nagler, Pamela L.; Glenn, Edward P.
View Citation
ennifer Pitt, Eloise Kendy, Karen Schlatter, Osvel Hinojosa-Huerta, Karl Flessa, Patrick B. Shafroth, Jorge Ramirez-Hernandez, Pamela Nagler, Edward P. Glenn, It takes more than water: Restoring the Colorado River Delta, Ecological Engineering, Available online 3 June 2017, ISSN 0925-8574, https://doi.org/10.1016/j.ecoleng.2017.05.028.

Year Published: 2017

The long-term legacy of geomorphic and riparian vegetation feedbacks on the dammed Bill Williams River, Arizona, USA

On alluvial rivers, fluvial landforms and riparian vegetation communities codevelop as a result of feedbacks between plants and abiotic processes. The influence of vegetation on river channel and floodplain geomorphology can be particularly strong on dammed rivers with altered hydrology and reduced flood disturbance. We used a 56-year series of...

Kui, Li; Stella, John C.; Shafroth, Patrick B.; House, P. Kyle; Wilcox, Andrew C.
View Citation
Kui, L., J.C. Stella, P.B. Shafroth, P.K. House, and A.C. Wilcox. 2017. The long-term legacy of geomorphic and riparian vegetation feedbacks on the dammed Bill Williams River, Arizona, USA. Ecohydrology 10:e1839.

Year Published: 2017

Landscape context and the biophysical response of rivers to dam removal in the United States

Dams have been a fundamental part of the U.S. national agenda over the past two hundred years. Recently, however, dam removal has emerged as a strategy for addressing aging, obsolete infrastructure and more than 1,100 dams have been removed since the 1970s. However, only 130 of these removals had any ecological or geomorphic assessments, and fewer...

Foley, Melissa M.; Magilligan, Francis J.; Torgersen, Christian E.; Major, Jon J.; Anderson, Chauncey; Connolly, Patrick J.; Wieferich, Daniel; Shafroth, Patrick B.; Evans, James E.; Infante, Dana M.; Craig, Laura
View Citation
Foley MM, Magilligan FJ, Torgersen CE,Major JJ, Anderson CW, Connolly PJ, Weiferich, D, Shafroth, PS, Evans, JE, Infante, D, Craig, LS. (2017) Landscape context and the biophysical response of rivers to dam removal in the United States. PLoS ONE 12(7): e0180107. https://doi.org/10.1371/journal.pone.0180107

Pre-USGS Publications

Ground-water recharge and riparian habitat enhancement from water discharged from New Waddell Dam into the Agua Fria River: Phase I--Planning and feasibility
Shafroth, P.B., J.C. Stromberg, D.T. Patten, A.E. Springer, and J.M. Wright. 1996. Ground-water recharge and riparian habitat enhancement from water discharged from New Waddell Dam into the Agua Fria River: Phase I--Planning and feasibility. Final Report to Arizona Dept. of Water Resources - Phoenix Active Management Area. Phoenix, AZ78+ap p.
River salinity has little influence on establishment of cottonwood and saltcedar. Research Information Bulletin 94-95
Shafroth, P.B., J.M. Friedman, and L.S. Ischinger. 1994. River salinity has little influence on establishment of cottonwood and saltcedar. Research Information Bulletin 94-95. NBS Information Bulletin.