Santa Rosa Island Noxious Weed Survey and Eradication

Beginning in 2006 Channel Islands Restoration worked for the Santa Barbara County Agricultural Commissioners Office to survey for and eradicate noxious invasive plants on Santa Rosa Island.

Channel Islands Restoration staff and volunteers joined other stakeholders in mapping all known populations of Yellowspine Thistle and Silverleaf Nightshade with GPS units. They then pruned the natives surrounding the invasive plants while also removing any growing fruits from the invasives in order to prepare the sites for herbicide treatment. Once the invasive plants were killed, we planted native plants in the open areas to impede invasives from resprouting.

For the nitty gritty details, visit the County of Santa Barbara's Official Project Page and read the final report here.

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Targeted Species:

 Yellowspine thistle ( Cirsium ochrocentrum )

Yellowspine thistle (Cirsium ochrocentrum)

Yellowspine thistle (Cirsium ochrocentrum) is designated by the California Department of Food and Agriculture as an "A" rated noxious weed. 1 Populations of this weed are of very limited distribution in California. In Santa Barbara County, it is only known to occur on Santa Rosa Island. Large infestations could ruin a landscape for rangeland, recreation, and wildlife habitat. - Santa Barbara Agricultural Commissioner.

Silverleaf nightshade (Solanum elaeagnifolium), also known as white horsenettle, is designated by the California Department of Food and Agriculture as a "B" rated noxious weed.2

Populations of this weed are of limited distribution in California. In Santa Barbara County it has been found on Santa Cruz Island from the Christy Barn area to the Christy airfield area and in Cebada Canyon, but is still very localized. It is found on Santa Rosa Island as well. These Channel Islands populations have received repeated treatments as part of the SBCWMA's Santa Rosa Island Noxious Weed Survey and Eradication Project. A population was found in 2009, and treated [by CIR], on the San Marcos Foothills. Additional historical collections have been made at the Bishop Ranch near Goleta, along a Solvang roadside, along Meigs Road in Santa Barbara, and at the mouth of Rattlesnake Canyon.

 Silverleaf nightshade ( Solanum elaeagnifolium )

Silverleaf nightshade (Solanum elaeagnifolium)


1 "A" rated noxious weeds are plants of known economic importance subject to enforcement action and are the highest priority for eradication by the CDFA and the SBCWMA. Populations of this weed are of very limited distribution in California. In Santa Barbara County, it is only known to occur on Santa Rosa Island. Large infestations could ruin a landscape for rangeland, recreation and wildlife habitat.

2 "B" rated noxious weeds are plants of know economic importance subject to enforcement action and are a high priority for control by the CDFA and the SBCWMA.

 

Santa Barbara Agricultural Commissioner.