Impacts

Native Vegetation -

• Tamarisk populations develop in dense thickets, with as many as 3,000 plants per acre, which can prevent the establishment of native vegetation (e.g., cottonwoods, willows, sage, grasses, and forbs).
• Due to the depth of their extensive root systems tamarisk draw more salts from the groundwater than native vegetation. These salts are excreted through tamarisk leaf glands and deposited on the ground with the leaf litter. This can result in a substantial rise in soil salinity and prevent the germination of many native plants.

Wildfire -

• The high amount of leaf litter that tamarisk produces increases the frequency and intensity of wildfires. These fires kill native vegetation such as cottonwoods and willows but stimulate tamarisk growth.

Wildlife and Livestock -

• Tamarisk invasions extensively degrade terrestrial habitat which leads to a loss of wildlife biodiversity in the stream corridor.
• Dense tamarisk stands affect livestock by reducing forage and preventing access to surface water.
• Tamarisk seeds and leaves are of little nutritional value to most wildlife and livestock.
• Dense tamarisk stands on stream banks accumulate sediment in their extensive root systems, gradually narrowing stream channels and increasing flooding potential. These changes in stream morphology can impact critical habitat for endangered fish.

People -

• Aesthetic values of the stream corridor are degraded by solid stands of tamarisk that exclude diverse vegetation and limit wildlife and bird viewing opportunities.
• Tamarisk block access to streams for recreation (e.g., boating, fishing, hunting, bird watching).
• Dense tamarisk stands on stream banks accumulate sediment in their extensive root systems, gradually narrowing stream channels and increasing flooding potential.

Water -

• Tamarisk has a reputation for using significantly more water than the native vegetation that it displaces. This non-beneficial user of the West’s limited water resources has been reported to dry up springs, wetlands, and riparian areas by lowering water tables.

For a more extensive discussion please refer to Tamarisk Ecology and Impacts.

Citations

Carpenter, A. 1998. Element Stewardship Abstract for Tamarix ramosissima Lebedour, Tamarix pentandra Pallas, Tamarix chinensis Loureiro, and Tamarix parviflora De Candolle. The Nature Conservancy, Arlington, Virginia

DeLoach, J. 1997. Effects of Biological Control of Saltcedar (Tamarix ramosissima) on Endangered Species: Biological Assessment. U.S. Department of Agriculture, Temple, Texas.

Weeks, E., H. Weaver, G. Campbell and B. Tanner, 1987. Water use by saltcedar and by replacement vegetation in the Pecos River floodplain between Acme and Artesia, New Mexico. U.S. Geological Survey, Reston, Virginia.