What is tamarisk?
Tamarisk is an invasive shrub or small tree that is found across the American West. Also known as saltcedar, tamarisk favors sites that are inhospitable to native streamside plants because of high salinity, low water availability, and altered streamflow regimes created by dams. Researchers debate the extent of tamarisk’s negative impacts, but this invasive species can and does alter habitat quality for some wildlife, water use by floodplain vegetation, and the frequency and intensity of wildfires.
One successful tamarisk control method is the introduction of a leaf-eating beetle from the tamarisk’s native range in Asia. Where tamarisks are declining, USGS scientists are studying how ecosystems respond to the removal of this invasive species.
Learn more: Southwestern Riparian Zones, Tamarisk Plants, and the Tamarisk Beetle
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The Transformation of dryland rivers: The future of introduced tamarisk in the U.S.
Tamarix spp. (tamarisk or saltcedar), a shrub-like tree, was intentionally introduced to the U.S. from Asia in the mid-1800s. Tamarisk thrives in today’s human-altered streamside (riparian) habitats and can be found along wetlands, rivers, lakes, and streams across the western U.S. In 2001, a biological control agent, Diorhabda spp. (tamarisk leaf...
Nagler, Pamela L.; Hull, Julia B.; van Riper, Charles; Shafroth, Patrick B.; Yackulic, Charles B.
Invasive species research—Science for detection, containment, and control
Invasive species research within the U.S. Geological Survey’s Ecosystems Mission Area focuses on invasive organisms throughout the United States. U.S. Geological Survey scientists work with partners in the Department of the Interior, other Federal, State and Territorial agencies, Tribes, industry, and agriculture to provide the information needed...
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Population dynamics of the northern tamarisk beetle (Diorhabda carinulata) in the Colorado River Basin
Throughout the Southwestern United States, riparian systems contain narrow belts of vegetation along streams and rivers. Although only a small percentage of the total land cover, this ecosystem is important for maintaining high species diversity and population densities of birds. Anthropogenic changes to Western riverine systems have enhanced...
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A satellite model of Southwestern Willow Flycatcher (Empidonax traillii extimus) breeding habitat and a simulation of potential effects of tamarisk leaf beetles (Diorhabda spp.), southwestern United States
Executive Summary The study described in this report represents the first time that a satellite model has been used to identify potential Southwestern Willow Flycatcher (Empidonax traillii extimus) (hereinafter referred to as “flycatcher”) breeding habitat rangewide for 2013–15. Fifty-seven Landsat scenes were required to map the...
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Influences of the Tamarisk Leaf Beetle (Diorhabda carinulata) on the diet of insectivorous birds along the Dolores River in Southwestern Colorado
We examined the effects of a biologic control agent, the tamarisk leaf beetle (Diorhabda carinulata), on native avifauna in southwestern Colorado, specifically, addressing whether and to what degree birds eat tamarisk leaf beetles. In 2010, we documented avian foraging behavior, characterized the arthropod community, sampled bird diets, and...
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Applying remote sensing to invasive species science—A tamarisk example
The Invasive Species Science Branch of the Fort Collins Science Center provides research and technical assistance relating to management concerns for invasive species, including understanding how these species are introduced, identifying areas vulnerable to invasion, forecasting invasions, and developing control methods. This fact sheet considers...
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Saltcedar (Tamarix spp.) and Russian Olive (Elaeagnus angustifolia) in the Western United States-A Report on the State of the Science
The Salt Cedar and Russian Olive Control Demonstration Act of 2006 (Public Law 109-320) directs the Department of the Interior to submit a report to Congress that includes an assessment of several issues surrounding these two nonnative trees, now dominant components of the vegetation along many rivers in the Western United States. This report was...
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Saltcedar 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...
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Tamarisk control, water salvage, and wildlife habitat restoration along rivers in the western United States
In the latter part of the 19th century, species of the nonnative shrub tamarisk (also called saltcedar; for example, Tamarix ramosissima, T. chinensis) were introduced to the United States for use as ornamental plants for erosion control. By 1877, some naturalized populations had become established, and by the 1960s, tamarisk was present along...
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Weather and evapotranspiration studies in a saltcedar thicket, Arizona
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Introduction, spread, and areal extent of saltcedar (Tamarix) in the Western States
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Invasive Saltcedar and Russian Olive Trees Consume Similar Amounts of Water as Native Cottonwoods and Willows, Wildlife Effects Mixed
Long considered heavy water users and poor wildlife habitat, non-native saltcedar and Russian olive trees that have spread along streams and water bodies in the West may not be as detrimental to wildlife and water availability as believed.
Saltcedar with buds and a pollinator
Saltcedar with buds and a pollinator
Erosion of invasive saltcedar
Erosion of invasive saltcedar
Anatomical changes in rings of buried saltcedar stems
Anatomical changes in rings of buried stems can be used to date stratigraphy. Saltcedar stem cross-section cut 2.8 m below the ground surface. 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. (Friedman and
...
A beetle introduced to the US to control saltcedar has dispersed
A beetle introduced to the US to control saltcedar has dispersed to the Middle Rio Grande. This natural-color image by DigitalGlobe, Inc. on July 18, 2016 shows saltcedar defoliated by the beetle (purple) at the confluence of the Rio Puerco and the Rio Grande. If the beetle kills large areas of saltcedar, subsequent floods could accelerate erosion in tributaries, leading
...
Setting up a transect to study tamarisk
What the beginning of a Tamarix transect looks like. Each transect (using a tape measure in this case) travels perpendicular to the river and ranges from tens of feet to hundreds of feet. Along the transect we collect information about plant community composition, riparian zone architecture, light, leaf litter depth, and soil chemistry (fall 2010).
Taking measurements in a tamarisk thicket
USGS scientist collecting data on one of our Colorado River Tamarix transects. These are difficult data to collect due to dense thickets Tamarisk can create (spring 2014).
Using lidar to depict the influence of the tamarisk beetle on tamarisk
Panels A and B are high resolution, multispectral imagery at the Kanab Creek confluence with the Colorado River in Grand Canyon showing dense stands of tamarisk vegetation that was green and healthy in May 2009 (panel A), but brown and defoliated in May 2013 due to herbivory by the tamarisk beetle (panel B). Panel C shows a lidar and multispectral image-based
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Tamarisk defoliation
Extensive defoliation of tamarisk (orange/brown vegetation throughout mid-ground) along the Virgin River, Arizona, 2009. Photo by Patrick Shafroth, USGS.
Tamarisk or saltcedar
Invasive Tamarisk or saltcedar as it is known, growing on the side of a river. Photo by NASA.
Invasive tamarisk on the Colorado River.
This image is of invasive tamarisk (salt cedar) growing on the banks of the Colorado River.
PubTalk 8/2010 — Invasives and Wildfires in the West
New Crossroads in Science, Policy, and Management
by Julio Betancourt, Sr. Scientist and Desert Ecologist
- Exponential spread of non-native grasses is a pressing environmental issue in American Deserts
- Invasive grasses increased fuel continuity and large wildfires in desert scrub that previously experienced little or no
The northern tamarisk beetle (Diorhabda carinulata)
The northern tamarisk beetle (Diorhabda carinulata) from a Fukang, China lab colony at USDA/ARS Quarantine in Temple, Texas.