Jonathan Friedman is a hydrologist at the Fort Collins Science Center. Since joining the Fort Collins Science Center in 1993, he 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.
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We examined channel flow and suspended sediment transport processes within the lower Rio Puerco arroyo, located in semi-arid north-central New Mexico, in an attempt to answer the question: Why did arroyo incision stop by about 1936? Channel flow model results show that in the narrow, incised channel of 1936, the boundary shear stress during a...
Griffin, Eleanor R.; Friedman, Jonathan M. We documented arroyo evolution at the tree, trench, and arroyo scales along the lower Rio Puerco and Chaco Wash in northern New Mexico, USA. We excavated 29 buried living woody plants and used burial signatures in their annual rings to date stratigraphy in four trenches across the arroyos. Then, we reconstructed the history of arroyo evolution by...
Friedman, Jonathan M.; Vincent, Kirk R.; Griffin, Eleanor R.; Scott, Michael L.; Shafroth, Patrick B.; Auble, Gregor T. Evolution has contributed to the successful invasion of exotic plant species in their introduced ranges, but how evolution affects particular control strategies is still under evaluation. For instance, classical biological control, a common strategy involving the utilization of highly specific natural enemies to control exotic pests, may be...
Williams, Wyatt I.; Friedman, Jonathan M.; Gaskin, John F.; Norton, Andrew P. Distributions of woody vegetation on floodplain surfaces affect flood-flow erosion and deposition processes. A large flood along the lower Rio Puerco, New Mexico, in August 2006 caused extensive erosion in a reach that had been sprayed with herbicide in September 2003 for the purpose of saltcedar (Tamarix spp.) control. Large volumes of sediment,...
Griffin, Eleanor R.; Perignon, Mariela C.; Friedman, Jonathan M.; Tucker, Gregory E. A new 368-year tree-ring chronology (A.D. 1643–2010) has been developed in western North Dakota using plains cottonwood (Populus deltoides subsp. monilifera) growing on the relatively undisturbed floodplain of the Little Missouri River in the North Unit of Theodore Roosevelt National Park. We document many slow-growing living trees...
Edmonson, Jesse; Friedman, Jonathan; Meko, David; Touchan, Ramzi; Scott, Julian; Edmonson, Alan The spatial distribution of riparian vegetation can strongly influence the geomorphic evolution of dryland rivers during large floods. We present the results of an airborne lidar differencing study that quantifies the topographic change that occurred along a 12 km reach of the Lower Rio Puerco, New Mexico, during an extreme event in 2006....
Perignon, M. C. ; Tucker, G.E.; Griffin, Eleanor R.; Friedman, Jonathan M. The Colorado River and its riverine resources have undergone profound changes since completion of Glen Canyon Dam in 1963, as every river runner with any history in Grand Canyon will attest. Long-term monitoring data are difficult to obtain for high-value resource areas (Webb et al. 2009), particularly in remote parts of national parks, yet these...
Webb, R.H.; Belnap, J.; Scott, M. L.; Friedman, J. M.; Esque, T. C. We review the use of tree rings to date flood disturbance, channel change, and sediment deposition, with an emphasis on rivers in semi-arid landscapes in the western United States. As watershed area decreases and aridity increases, large floods have a more pronounced and sustained effect on channel width and location, resulting in forest area-age...
Merigliano, M.F.; Friedman, J. M.; Scott, M. L.
Areal cover and occupancy of woody riparian species near 456 streamgages in the western United States were obtained from site visits during the growing seasons of 1996-2002. We made concomitant estimates of grazing intensity, channel stabilization and incision, gradient, sediment particle size, and nearby planting of Russian olive. The purpose of...
Auble, Gregor T.; Friedman, Jonathan M.; Shafroth, Patrick B.; Merigliano, Michael F.; Scott, Michael L. Russian olive (Elaeagnus angustifolia L.), a Eurasian tree now abundant along rivers in western North America, has an apparent southern distribution limit running through southern California, Arizona, New Mexico and Texas. We used field observations to precisely define this limit in relation to temperature variables. We then investigated whether...
Guilbault, Kimberly R.; Brown, C.S.; Friedman, J.M.; Shafroth, P.B. To explore latitudinal genetic variation in cold hardiness and leaf phenology, we planted a common garden of paired collections of native and introduced riparian trees sampled along a latitudinal gradient. The garden in Fort Collins, Colorado (latitude 40.6°N), included 681 native plains cottonwood (Populus deltoides subsp. monilifera) and...
Friedman, Jonathan M.; Roelle, James E.; Cade, Brian S. Certain phenotypic traits of plants vary with latitude of origin. To understand if tannin concentration varies among populations of tamarisk (Tamarix spp.) according to a latitudinal gradient, an analytical method was adapted from an enological tannin assay. The tannin content (wet basis) of tamarisk foliage collected from 160 plants grown in a...
Hussey, A.M.; Kimball, B.A.; Friedman, J.M.