Background and Program Development: Lake Mead National Recreation Area has many miles of tamarisk thickets along the shores of Lake Mead and Lake Mojave and in numerous springs and canyons. Records reveal that some tamarisk control work was conducted in the 1970's by some foresighted park rangers, however this work was left abandoned and unmaintained. Some tamarisk control projects have been conducted annually since the early 1980's by park rangers in the Black Canyon to allow access to beach camping along the Colorado River. In 1986 the parks' natural resource management division began a more concerted effort by inventorying and mapping vegetation resources at more than 30 isolated springs and undertook a study on tamarisk control methods. Although the spring inventory was very crude it was the most helpful management tool to proceed before undertaking a tamarisk control program. Resource managers then decided to develop priorities focusing on the springs which form isolated islands of biological diversity amongst a sea of arid landscape.
Implementation: Eradication efforts began in 1988 by forming small groups of 2-4 employees and volunteers that worked in various areas ranging in size from one acre to several miles of drainage. The larger areas with high salt cedar density were removed using prison crews and trained park service restoration crews. The areas of highest density and remoteness were accomplished using hot shot firefighter crews. Park staff maintains areas free of tamarisk after the initial labor intensive removals are completed.
Restoration: Post tamarisk removal site recovery success has kept managers positive by directly observing the fruition of their efforts. Re-establishment of native vegetation has been impressive by both natural recolonization and active revegetation by transplanting. Specific project results are presented from data collected from vegetation plots at the Sacatone Spring experimental restoration site.
Accomplishments: Eighteen spring drainages have been successfully restored by the eradication and maintenance of tamarisk including large dense areas from sites 1 to 7 miles in length. Achieved excellent revegetation success at six sites by transplanting native trees. Developed and refined four effective tamarisk control methods using prescribed fire, cut-stump, low volume basal herbicide application, and heavy equipment. Conducted large scale salt cedar removal projects at four beaches on Lake Mojave by using heavy equipment and fire.
Current and Future Plans: Currently initiating a relatively large scale riparian restoration project at the tamarisk dominated Las Vegas Wash, methods of control will include heavy equipment, fire, and flooding. Developing a GIS map of tamarisk control areas and zero tolerance zones to assist with maintenance scheduling and planning. Finalizing the Pesticide Use Plan for Tamarisk Control. Funding proposals continue to be submitted for riparian restoration at three other high priority sites. Pursuing a National Park Service wide approach to managing salt cedar populations and the possible development of exotic plant control crews for project implementation.
[Note: 2 tables with graphics not included in the internet version.]
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