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.
In the western United States, the majority of riparian restoration projects involve control of these, and other, non-native species. We have researched many aspects of these plants, such as understanding environmental factors required for establishment, growth, and spread, as well as interactions with channel change, riparian water use, and wildlife. Current projects are focused on understanding vegetation recovery following biological control of tamarisk, including detailed studies on the Virgin and Colorado rivers; on the dynamics of riparian vegetation following extensive removal of Russian Olive on the Escalante River; and on understanding the distribution and abundance of Siberian Elm in the Upper Colorado, Platte, and Rio Grande basins. Our work on riparian invasives overlaps with other projects, including Large-scale streamflow experiments, and Science to inform riparian ecosystem restoration.
Below are other science projects associated with this project.
Riparian Ecology
Below are publications associated with this project.
Tamarisk beetle (Diorhabda spp.) in the Colorado River basin: Synthesis of an expert panel forum
Distribution of invasive and native riparian woody plants across the western USA in relation to climate, river flow, floodplain geometry and patterns of introduction
Riparian restoration in the context of Tamarix control in the western United States: Chapter 23
The influence of chilling requirement on the southern distribution limit of exotic Russian olive (Elaeagnus angustifolia) in western North America
Distribution and abundance of saltcedar and Russian olive in the western United States
Saltcedar and Russian Olive Control Demonstration Act Science Assessment
Rethinking avian response to Tamarix on the lower Colorado River: A threshold hypothesis
Altered stream-flow regimes and invasive plant species: The Tamarix case
Hybridization of Tamarix ramosissima and T. chinensis (saltcedars) with T. aphylla (athel) (tamaricaceae) in the southwestern USA dertermined from DNA sequence data
Control of Tamarix in the western United States: Implications for water salvage, wildlife use, and riparian restoration
Dominance of non-native riparian trees in western USA
Biology, ecology and management of Elaeagnus angustifolia L. (Russian olive) in western North America
- Overview
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.
In the western United States, the majority of riparian restoration projects involve control of these, and other, non-native species. We have researched many aspects of these plants, such as understanding environmental factors required for establishment, growth, and spread, as well as interactions with channel change, riparian water use, and wildlife. Current projects are focused on understanding vegetation recovery following biological control of tamarisk, including detailed studies on the Virgin and Colorado rivers; on the dynamics of riparian vegetation following extensive removal of Russian Olive on the Escalante River; and on understanding the distribution and abundance of Siberian Elm in the Upper Colorado, Platte, and Rio Grande basins. Our work on riparian invasives overlaps with other projects, including Large-scale streamflow experiments, and Science to inform riparian ecosystem restoration.
- Science
Below are other science projects associated with this project.
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, climate change, invasive species, and ecological restoration. Investigations take place on a range of scales. For... - Publications
Below are publications associated with this project.
Filter Total Items: 14Tamarisk beetle (Diorhabda spp.) in the Colorado River basin: Synthesis of an expert panel forum
Executive Summary In 2001, the U.S. Department of Agriculture approved the release of a biological control agent, the tamarisk beetle (Diorhabda spp.), to naturally control tamarisk populations and provide a less costly, and potentially more effective, means of removal compared with mechanical and chemical methods. The invasive plant tamarisk (Tamarix spp.; saltcedar) occupies hundreds of thousandDistribution of invasive and native riparian woody plants across the western USA in relation to climate, river flow, floodplain geometry and patterns of introduction
Management of riparian plant invasions across the landscape requires understanding the combined influence of climate, hydrology, geologic constraints and patterns of introduction. We measured abundance of nine riparian woody taxa at 456 stream gages across the western USA. We constructed conditional inference recursive binary partitioning models to discriminate the influence of eleven environmentaRiparian restoration in the context of Tamarix control in the western United States: Chapter 23
This chapter focuses on the restoration of riparian systems in the context of Tamarix control—that is, Tamarix-dominated sites are converted to a replacement vegetation type that achieves specific management goals and helps return parts of the system to a desired and more natural state or dynamic. It reviews research related to restoring native riparian vegetation following tamarix control or remoThe influence of chilling requirement on the southern distribution limit of exotic Russian olive (Elaeagnus angustifolia) in western North America
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 lack of cold temperatures south of the limit may preDistribution and abundance of saltcedar and Russian olive in the western United States
Over the past century, two introduced Eurasian trees, saltcedar (Tamarix spp.) and Russian olive (Elaeagnus angustifolia) have become wide spread on western United States of American (U.S.) rivers. This paper reviews the literature on the following five key areas related to their distribution and abundance in the western United States: (1) the history of introduction, planting, and spread of saltcSaltcedar and Russian Olive Control Demonstration Act Science Assessment
The primary intent of this document is to provide the science assessment called for under The Saltcedar and Russian Olive Control Demonstration Act of 2006 (Public Law 109-320; the Act). A secondary purpose is to provide a common background for applicants for prospective demonstration projects, should funds be appropriated for this second phase of the Act. This document synthesizes the state-of-thRethinking avian response to Tamarix on the lower Colorado River: A threshold hypothesis
Many of the world's large river systems have been greatly altered in the past century due to river regulation, agriculture, and invasion of introduced Tamarix spp. (saltcedar, tamarisk). These riverine ecosystems are known to provide important habitat for avian communities, but information on responses of birds to differing levels of Tamarix is not known. Past research on birds along the ColoradoAltered stream-flow regimes and invasive plant species: The Tamarix case
Aim: To test the hypothesis that anthropogenic alteration of stream-flow regimes is a key driver of compositional shifts from native to introduced riparian plant species. Location: The arid south-western United States; 24 river reaches in the Gila and Lower Colorado drainage basins of Arizona. Methods: We compared the abundance of three dominant woody riparian taxa (native Populus fremontii and SaHybridization of Tamarix ramosissima and T. chinensis (saltcedars) with T. aphylla (athel) (tamaricaceae) in the southwestern USA dertermined from DNA sequence data
Morphological intermediates between Tamarix ramosissima or T. chinensis (saltcedars) and T. aphylla (athel) were found recently in three locations in the southwestern USA, and were assumed to be hybrids or a previously unreported species. We sequenced chloroplast and nuclear DNA from putative parental and hybrid morphotypes and hybrid status of morphological intermediates was supported. ChloroplasControl of Tamarix in the western United States: Implications for water salvage, wildlife use, and riparian restoration
Non-native shrub species in the genus Tamarix (saltcedar, tamarisk) have colonized hundreds of thousands of hectares of floodplains, reservoir margins, and other wetlands in western North America. Many resource managers seek to reduce saltcedar abundance and control its spread to increase the flow of water in streams that might otherwise be lost to evapotranspiration, to restore native riparian (sDominance of non-native riparian trees in western USA
Concern about spread of non-native riparian trees in the western USA has led to Congressional proposals to accelerate control efforts. Debate over these proposals is frustrated by limited knowledge of non-native species distribution and abundance. We measured abundance of 44 riparian woody plants at 475 randomly selected stream gaging stations in 17 western states. Our sample indicates that TamariBiology, ecology and management of Elaeagnus angustifolia L. (Russian olive) in western North America
Elaeagnus angustifolia (Russian olive) is an alien tree that is increasingly common in riparian habitats of western North America. This paper reviews the pertinent scientific literature in order to determine the status of E. angustifolia as a riparian invader and to suggest ecological reasons for its success. Elaeagnus angustifolia meets the biogeographic, spread, and impact criteria for invasive