About Tamarisk (also called Salt Cedar)

Introduction of Tamarisk

• Tamarisk is originally from Europe, Asia, and Africa.

• Tamarisk was intentionally brought to the United States in the 1800s as ornamental trees because

• they grow fast.

• they add interesting color and texture to landscaping.

• they are pretty.

• Tamarisk is primarily found in the west.

Problems

• Tamarisk invasions are among top threats to the health of western riparian ecosystems.

• They out-compete native woody vegetation and often result in a monoculture.

• Tamarisk can spread very rapidly.

• Each flower produces thousands of tiny seeds.

• Their seeds are dispersed by wind and water.

• They also reproduce vegetatively (through roots).

• Heavy infestations of tamarisk reduce diversity and value of the riparian community.

• Heavy infestations of tamarisk alter ecosystems and degrade water and soil quality.

• In addition to reducing native plants, tamarisk invasions exclude species that are dependent on native plants.

• Full-blown infestations of tamarisk may take as little as 20 years.

• They have no native enemies in the United States.

• Salts drawn from groundwater are excreted through their leaf glands and deposited on ground and water surfaces. 

• Dense stands of tamarisk can also compromise the physical integrity of the stream channel. 

The water issue

• Although the evapo-transpiration rate of tamarisk appears to be similar to cottonwoods and willows, the root system of a mature tamarisk tree is up to ten times deeper than native cottonwoods and willows. 

• Tamarisk plants have the ability to lower the water table further than their native woody counterparts; this may be particularly noticeable and challenging during drought years or during low water flows.

• The deep roots of tamarisk extend as far as 100 feet, enabling tamarisk to colonize adjacent upland vegetation zones and consume much more water than native vegetation it displaces.

• The Tamarisk Coalition has estimated within the west, the average ratio of land area now sustaining tamarisk that could be occupied by native vegetation is approximately 25% for cottonwood/willow communities with the remaining 75% percentage of land capable of supporting dry-land brush type of plant communities.