Spring 2005 Udpate

Invasive Removal Program In Full Swing

The program to control invasive non-native plant species in riparian and wetland habitats within the Carlsbad Hydrologic Unit (CHU) (initiated by the $3.9 million Proposition 13 Invasives Removal/Watershed Protection Program Grant) is in full swing. In addition to our preliminary estimate of 278 acres, we have located an additional 172 acres of invasive species bringing our total estimate to 450 acres. Treatment, monitoring and the development of management strategies by watershed are important tasks for this program.

The main invasive non-native plant species include giant reed (Arundo donax), pampas grass (Cortaderia selloana ), tamarisk (Tamarix ramosissima ) and castor bean (Ricinus communis ). These plants do extensive damage to private property and natural resources. They contribute to flood damage, increase the risks associated with fire, and degrade native habitat. They also spread aggressively, potentially onto neighboring properties, making them difficult to control. Public and private landowners with invasive plant species on their property are contacted and written permission is obtained prior to initiation of any work.

The targeted plants are treated by applying Rodeo ® or Round-up ® herbicide to the plant. Both herbicides pose no risk to humans or other animals when used properly. Rodeo ® is certified by the U. S. Environmental Protection Agency for use in and around wetlands. Fully licensed and insured professionals carry out the applications. See our Herbicide Usage Policy.

All treated invasive plants are mulched on the site if possible. This reduces the chances of infestation by other non-native plant species. Extra care is taken to avoid impacting native vegetation during the mulching process.

The next phase in the process involves re-vegetation. Native plants will be planted in many areas after invasive plants have been treated. We work closely with the property owner to cater our activities to their needs and concerns. The arundo and pampas grass treatments along the creek and lagoons of the CHU appear to be successful. One of the Harmony Grove properties is improving dramatically with the removal of Arundo. Re-vegetating the area with native shrubs and trees will greatly improve the riparian habitat which ultimately improves the quality of water entering the lagoons and creeks of the Carlsbad Hydrologic Unit.