The U.S. currently spends approximately $120 billion annually on the control and impacts of invasive species. Once established in natural areas, invasive plants displace native vegetation and greatly reduce wildlife diversity. In addition, invasive plants fuel wildfires, degrade grazing land, contribute to soil erosion, clog streams and rivers, increase flooding, and have negative impacts on our local water supply.
INVASIVE PLANT CONTROL PROJECTS
Greater Los Angeles County Region
The Los Angeles County Flood Control District, on behalf of the GLAC IRWMP, was awarded a $25 million Prop 50 grant in 2007. The FCD accepted the grant on behalf of fourteen projects and project managers, one of which is the Council for Watershed Health. Our project
is the San Gabriel Valley Arundo Removal Project, designed to restore natural riparian
habitat and increase surface water flow to the Rio Hondo percolation basins in the
San Gabriel Valley. The project will remove 24 net acres of Arundo donax (Arundo
or giant reed), which classified federally and by California as a noxious weed.
The Council for Watershed Health has contracted with Riparian Repairs to conduct the work.
Contact us for more information.
The following description of Arundo is taken from Noxious wildland weeds of California,
C. Bossard, J. Randall, & M. Hoshovsky (Eds), and references therein.
Arundo displaces native plants and associated wildlife species as a consequence
of the massive stands it forms. Several special status species are associated with
California’s semi-arid riparian zones all of which are negatively affected by the
replacement of willow/cottonwood riparian vegetation by Giant reed. Unlike native
riparian plants, Arundo provides little shading to the in-stream habitat, leading
to increased water temperatures and reduced habitat quality for aquatic wildlife.
Arundo is also suspected of altering hydrological regimes and reducing groundwater
availability by transpiring large amounts of water from semi-arid aquifers. It alters
channel morphology by retaining sediments and constricting flows, and in some cases
may reduce stream navigability. Dense growths present fire hazards, often near urbanized
areas, more than doubling the available fuel for wildfires and promoting post-fire
regeneration of even greater quantities of Giant reed. Uprooted plants also pose
clean-up problems when deposited on banks or in downstream estuaries and during
floods create hazards where trapped behind bridges and other structures.