Jonathan Friedman, PhD
Jonathan Friedman is a Hydrologist at the Fort Collins Science Center.
Since joining the Fort Collins Science Center in 1993, Jonathan has devoted his career to studying interactions among riparian vegetation, river flow and channel change. Present research topics include use of riparian tree rings to reconstruct past river flow, quantification of federal reserved water rights, and determination of the effect of riparian vegetation on bank stability.
Professional Experience
1993-present, Research Hydrologist, USGS Fort Collins Science Center, Fort Collins, CO
1990-1993, Hydrologist, USGS Water Resources Division, Lakewood, CO
1988-1990, Community College Instructor, Bellevue Community College, Olympic College and Front Range Community College, Washington and Colorado.
1988 Assistant Natural Area Scientist, Washington Natural Heritage Program, Olympia, Washington
Education and Certifications
Ph.D. Environmental, Population and Organismic Biology, University of Colorado, Boulder, 1993
M.S. Oceanography and Limnology, University of Wisconsin, Madison, 1987
B.S. Biology, Massachusetts Institute of Technology, 1983
Affiliations and Memberships*
Ecological Society of America
American Geophysical Union
Science and Products
Vegetation responses to dam removal
Extreme floods, channel change, and riparian forests along ephemeral streams
Potential responses of riparian vegetation to dam removal
Effects of physical disturbance and granivory on establishment of native and alien riparian trees in Colorado, USA
High flow and riparian vegetation along the San Miguel River, Colorado
Classification of river regimes: A context for hydroecology
The disparity between extreme rainfall events and rare floods - with emphasis on the semi-arid American West
Floods, flood control, and bottomland vegetation
Mortality of riparian box elder from sediment mobilization and extended inundation
Downstream effects of dams on channel geometry and bottomland vegetation: Regional patterns in the Great Plains
Riparian cottonwood response to watertable declines
Non-USGS Publications**
**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
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Filter Total Items: 88
Vegetation responses to dam removal
No abstract available.AuthorsPatrick B. Shafroth, Jonathan M. Friedman, Gregor T. Auble, Michael L. ScottExtreme floods, channel change, and riparian forests along ephemeral streams
The geomorphic effectiveness of extreme floods increases with aridity and decreasing watershed size. Therefore, in small dry watersheds extreme floods should control the age structure and spatial distribution of populations of disturbance-dependent riparian trees. We examined the influence of extreme floods on the bottomland morphology and forest of ephemeral streams in a semiarid region. Along siAuthorsJ. M. Friedman, V.J. LeePotential responses of riparian vegetation to dam removal
Throughout the world, riparian habitats have been dramatically modified from their natural condition. Dams are one of the principal causes of these changes, because of their alteration of water and sediment regimes (Nilsson and Berggren 2000). Because of the array of ecological goods and services provided by natural riparian ecosystems (Naiman and Decamps 1997), their conservation and restorationAuthorsP.B. Shafroth, J. M. Friedman, G.T. Auble, M.L. Scott, J.H. BraatneEffects of physical disturbance and granivory on establishment of native and alien riparian trees in Colorado, USA
In western North America, the alien Elaeagnus angustifolia L. invades riparian habitats usually dominated by pioneer woody species such as Populus deltoides Marshall ssp. monilifera (Aiton) Eckenwalder. We conducted manipulative field experiments to compare the importance of physical disturbance and granivory for seedling establishment of these two species. We planted seeds of both species in distAuthorsG.L. Katz, J. M. Friedman, S.W. BeattyHigh flow and riparian vegetation along the San Miguel River, Colorado
Riparian ecosystems are characterized by abundance of water and frequent flow related disturbance. River regulation typically decreases peak flows, reducing the amount of disturbance and altering the vegetation. The San Miguel River is one of the last relatively unregulated rivers remaining in the Colorado River Watershed. One goal of major landowners along the San Miguel including the Bureau of LAuthorsJ. M. Friedman, G.T. AubleClassification of river regimes: A context for hydroecology
Over the past 30 years, ecologists have demostrated the importance of flow and temperature as primary variables in driving running water, riparian and floodplain ecosystems. As it is important to assess the size and timing of discharge variations in relation to those in temperature, a method is proposed that uses multivariate techniques to separately classify annual discharge and temperature regimAuthorsW. R. Osterkamp, J. M. FriedmanThe disparity between extreme rainfall events and rare floods - with emphasis on the semi-arid American West
Research beginning 40 years ago suggested that semi-arid lands of the USA have higher unit discharges for a given recurrence interval than occur in other areas. Convincing documentation and arguments for this suspicion, however, were not presented. Thus, records of measured rainfall intensities for specified durations and recurrence intervals, and theoretical depths of probable maximum precipitatiAuthorsW. R. Osterkamp, J. M. FriedmanFloods, flood control, and bottomland vegetation
Bottomland plant communities are typically dominated by the effects of floods. Floods create the surfaces on which plants become established, transport seeds and nutrients, and remove establish plants. Floods provide a moisture subsidy that allows development of bottomland forests in arid regions and produce anoxic soils, which can control bottomland plant distribution in humid regions. Repeated fAuthorsJonathan M. Friedman, Gregor T. AubleMortality of riparian box elder from sediment mobilization and extended inundation
To explore how high flows limit the streamward extent of riparian vegetation we quantified the effects of sediment mobilization and extended inundation on box elder (Acer negundo) saplings along the cobble-bed Gunnison River in Black Canyon of the Gunnison National Monument, Colorado, USA. We counted and aged box elders in 144 plots of 37.2 m2, and combined a hydraulic model with the hydrologic reAuthorsJonathan M. Friedman, Gregor T. AubleDownstream effects of dams on channel geometry and bottomland vegetation: Regional patterns in the Great Plains
The response of rivers and riparian forests to upstream dams shows a regional pattern related to physiographic and climatic factors that influence channel geometry. We carried out a spatial analysis of the response of channel geometry to 35 dams in the Great Plains and Central Lowlands, USA. The principal response of a braided channel to an upstream dam is channel-narrowing, and the principal respAuthorsJ. M. Friedman, W. R. Osterkamp, M.L. Scott, G.T. AubleRiparian cottonwood response to watertable declines
No abstract available.AuthorsM.L. Scott, Patrick Shafroth, G.T. Auble, E. D. EgglestonNon-USGS Publications**
Friedman, J.M., M.L. Scott, and W.M. Lewis, Jr. 1995. Restoration of riparian forest using irrigation, artificial disturbance, and natural seedfall. Environmental Management. 19(4): 547-5.Auble, G.T., J.M. Friedman, and M.L. Scott. 1996. Test of a hydroperiod relation to predict changes in riparian vegetation. From big rivers to small streams. Kansas City, Missouri: Society of Wetland Scientists. p. 25-26.Friedman, J.M., G.T. Auble, and M.L. Scott. 1995. Geomorphic requirements for establishment and maintenance of cottonwood forest. Proceedings of the 46th annual meeting of the Great Plains Agricultural Council Forestry Committee. Great Plains Agricultural Council Publication No. 149. Manhattan, KS: Great Plains Agricultural Council. p. 80-88.
Friedman, J.M., M.L. Scott, G.T. Auble, and L.S. Ischinger. 1995. Plains cottonwood regenerates from natural seedfall on disturbed, irrigated sites. NBS Information Bulletin. Washington, DC: National Biological Service. 3 p.Auble, G.T., J.M. Friedman, and M.L. Scott. 1995. Regeneration processes and conservation of riparian forests in the Great Plains. Proceedings of the biodiversity conservation strategies for the Great Plains symposium. Austin, TX: The Nature Conservancy. p. 36-37.Auble, G.T., J.M. Friedman, M.L. Scott, and L.S. Ischinger. 1994. Geomorphic processes determine instream flow effects on cottonwood regeneration. NBS Information Bulletin 83. Washington, DC: U.S. Geological Survey. 1-3 p.Auble, G.T., M.L. Scott, J.M. Friedman, and L.S. Ischinger. 1994. Modeling effects of flow alteration on riparian vegetation. Research Information Bulletin 65. Washington, DC: National Biological Survey. 3 p.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.**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.
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*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government