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 an invasive species.

Related Content

Filter Total Items: 3

What is an invasive species and why are they a problem?

An invasive species is an introduced, nonnative organism (disease, parasite, plant, or animal) that begins to spread or expand its range from the site of its original introduction and that has the potential to cause harm to the environment, the economy, or to human health.

A few well-known examples include the

...Read Full Answer

How can I find the scientific names of plants and animals?

Finding the scientific name requires detective work, because there can be multiple common names that can vary geographically, and similar common names can refer to a variety of organisms. A good starting point is the Integrated Taxonomic Information System, a database of scientific and

...Read Full Answer

Why do animals and plants become endangered?

Generally speaking, endangered species are those animals and plants that are in decline and may be in danger of extinction. A threatened species is one that is likely to become endangered within the foreseeable future.

Read Full Answer
Filter Total Items: 1
Date published: April 28, 2010

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.

Filter Total Items: 11
Saltcedar with buds and a pollinator
January 25, 2017

Saltcedar with buds and a pollinator

Erosion of invasive saltcedar
January 25, 2017

Erosion of invasive saltcedar

Anatomical changes in rings of buried stems can be used to date stratigraphy.
January 25, 2017

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 others 2005, 2015).

A beetle introduced to the US to control saltcedar has dispersed to the Middle Rio Grande.
January 25, 2017

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 to siltation along the Rio Grande and in Elephant Butte Reservoir. 

A tape measure disappearing into a stand of tamarisk and a whiteboard containing information about the site.
December 30, 2016

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).

USGS researcher struggling to set up a line transect (tape measure) in a dense thicket of tamarisk.
December 30, 2016

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).

Looking down on the Colorado River, an image of healthy tamarisk in 2009 and dead tamarisk in 2013,
December 21, 2016

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 classification of tamarisk defoliation (“Tamarisk Decline” in legend) due to the tamarisk beetle along the Colorado River in Glen Canyon.

Extensive defoliation of tamarisk (orange/brown vegetation throughout mid-ground) along the Virgin River, Arizona, 2009.
November 28, 2016

Extensive defoliation of tamarisk (orange/brown vegetation throughout mid-ground) along the Virgin River, Arizona, 2009. Photo by Patrick Shafroth, USGS.

Invasive Tamarisk or saltcedar as it is known, growing on the side of a river.
October 28, 2016

Invasive Tamarisk or saltcedar as it is known, growing on the side of a river. Photo by NASA.

Invasive tamarisk on the Colorado River.
2012 (approx.)

This image is of invasive tamarisk (salt cedar) growing on the banks of the Colorado River. 

 The northern tamarisk beetle (Diorhabda carinulata) from a Fukang, China lab colony at USDA/ARS Quarantine in Temple, Texas.
2002 (approx.)

The northern tamarisk beetle (Diorhabda carinulata) from a Fukang, China lab colony at USDA/ARS Quarantine in Temple, Texas.