The Little Missouri River, flood plain and surrounding badlands in the North Unit of Theodore Roosevelt National Park. Leafless gray trees on the flood plain are mostly cottonwood, and dark green trees are rocky mountain juniper. Cottonwood stands occur in arc-shaped bands increasing in age with distance from the channel.
Jonathan M Friedman, PhD (Former Employee)
Science and Products
Reconstructing Flow History From Riparian Tree Rings
FORT aquatic scientists analyze rings of riparian trees relating tree growth and establishment to historical flow. They then use the tree rings to reconstruct the flow in past centuries. Flow reconstructions discover the frequency and magnitude of past droughts and floods—information that is essential for management of rivers and water supplies. They have pioneered the use of cottonwood, a...
Integrated River and Riparian Ecosystem Studies
FORT scientists study interactions among river flow, riparian vegetation and channel change at low elevations across the western United States. Cooperators include the National Park Service, Bureau of Land Management, U.S. Fish and Wildlife Service and Bureau of Reclamation. Research areas include reservoir management, control of invasive species, drought response and flood erosion after fires...
FORT Cottonwood Common Garden
FORT scientists established a Common Garden at the Colorado State Forest Service Nursery in Fort Collins, Colorado in 2005 to study the phenology of riparian cottonwood in relation to annual variation in temperature. Phenology is the seasonal timing of life history events including leaf opening, flowering, seed release, bud formation and leaf senescence.
Fort Collins Science Center Labs and Facilities
The Fort Collins Science Center has scientists working in several diverse locations as well as three in house highly specialized laboratories, studying subjects from molecular ecology to brown treesnakes, dendroecology to streamflows, and macroinvertebrate species to Burmese pythons. Our extraordinary scientists work in each of these locations advancing studies in their particular areas of study...
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 arroyo...
Riparian Ecology
Riparian ecologists at the Fort Collins Science Center study interactions among flow, channel change, and vegetation along rivers across the western United States and worldwide. Our work focuses on issues relevant to the management of water and public lands, including dam operation, invasive species, and ecological restoration. Investigations take place on a range of scales. For example...
The Little Missouri River, flood plain
The Little Missouri River, flood plain and surrounding badlands in the North Unit of Theodore Roosevelt National Park. Leafless gray trees on the flood plain are mostly cottonwood, and dark green trees are rocky mountain juniper. Cottonwood stands occur in arc-shaped bands increasing in age with distance from the channel.
Tree ring dating
Tamarisk stem cross-section cut 2.8 m below the ground surface showing how sediment deposition is dated using tree rings. Following initial burial of 68 cm in 1969, ring-width decreased, vessel size increased, and annual transitions became less distinct. After a second burial by 41 cm in 1972, annual transitions became indistinguishable.
Tamarisk stem cross-section cut 2.8 m below the ground surface showing how sediment deposition is dated using tree rings. Following initial burial of 68 cm in 1969, ring-width decreased, vessel size increased, and annual transitions became less distinct. After a second burial by 41 cm in 1972, annual transitions became indistinguishable.
Science and Products
Reconstructing Flow History From Riparian Tree Rings
FORT aquatic scientists analyze rings of riparian trees relating tree growth and establishment to historical flow. They then use the tree rings to reconstruct the flow in past centuries. Flow reconstructions discover the frequency and magnitude of past droughts and floods—information that is essential for management of rivers and water supplies. They have pioneered the use of cottonwood, a...
Integrated River and Riparian Ecosystem Studies
FORT scientists study interactions among river flow, riparian vegetation and channel change at low elevations across the western United States. Cooperators include the National Park Service, Bureau of Land Management, U.S. Fish and Wildlife Service and Bureau of Reclamation. Research areas include reservoir management, control of invasive species, drought response and flood erosion after fires...
FORT Cottonwood Common Garden
FORT scientists established a Common Garden at the Colorado State Forest Service Nursery in Fort Collins, Colorado in 2005 to study the phenology of riparian cottonwood in relation to annual variation in temperature. Phenology is the seasonal timing of life history events including leaf opening, flowering, seed release, bud formation and leaf senescence.
Fort Collins Science Center Labs and Facilities
The Fort Collins Science Center has scientists working in several diverse locations as well as three in house highly specialized laboratories, studying subjects from molecular ecology to brown treesnakes, dendroecology to streamflows, and macroinvertebrate species to Burmese pythons. Our extraordinary scientists work in each of these locations advancing studies in their particular areas of study...
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 arroyo...
Riparian Ecology
Riparian ecologists at the Fort Collins Science Center study interactions among flow, channel change, and vegetation along rivers across the western United States and worldwide. Our work focuses on issues relevant to the management of water and public lands, including dam operation, invasive species, and ecological restoration. Investigations take place on a range of scales. For example...
The Little Missouri River, flood plain
The Little Missouri River, flood plain and surrounding badlands in the North Unit of Theodore Roosevelt National Park. Leafless gray trees on the flood plain are mostly cottonwood, and dark green trees are rocky mountain juniper. Cottonwood stands occur in arc-shaped bands increasing in age with distance from the channel.
The Little Missouri River, flood plain and surrounding badlands in the North Unit of Theodore Roosevelt National Park. Leafless gray trees on the flood plain are mostly cottonwood, and dark green trees are rocky mountain juniper. Cottonwood stands occur in arc-shaped bands increasing in age with distance from the channel.
Tree ring dating
Tamarisk stem cross-section cut 2.8 m below the ground surface showing how sediment deposition is dated using tree rings. Following initial burial of 68 cm in 1969, ring-width decreased, vessel size increased, and annual transitions became less distinct. After a second burial by 41 cm in 1972, annual transitions became indistinguishable.
Tamarisk stem cross-section cut 2.8 m below the ground surface showing how sediment deposition is dated using tree rings. Following initial burial of 68 cm in 1969, ring-width decreased, vessel size increased, and annual transitions became less distinct. After a second burial by 41 cm in 1972, annual transitions became indistinguishable.
*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