The Lake Tahoe Basin Weeds Coordinating Group recently released its 2007 Annual Report. The LTBWCG completed detection surveys on over 1,180 miles of roads, monitored 520 sites including new and historical infestation sites and treated 21 acres to eradicate terrestrial weeds—a 32% decrease in the area required for treatment compared to 2006. In the area of education and outreach, the LTBWCG reached 1,080 people through trainings, events and workshops, performed 81 homeowner consultations and distributed over 6,200 brochures. The Lake Tahoe Basin Weeds Coordinating Group is a diverse partnership of agencies and community members dedicated to preventing and controlling invasive wee species in the Lake Tahoe Basin.
Early Detection and Eradication Network
Weed invasion pressure is considered high in the Lake Tahoe Basin due to the bistate border location and nexus of travel corridors, historical escaped ornamental weed populations, construction and road maintenance activities and the seasonal influx of tourists. The invasive nature of these problem weeds and the difficulty and cost in removing them once established, lends an inherent urgency to detect and eradicate new infestations quickly.
An early detection and rapid response network is coordinated by the LTBWCG to ensure that the entire basin is
surveyed annually.
2007 Highlights
Detection and Mapping
• Detection surveys were completed on over 1880 miles of roads
• 520 sites were monitored in the Lake Tahoe Basin, including historical and new infestation sites
Control and Eradication
• 21 net acres in the Basin were treated to eradicate terrestrial weeds. Compared with 2006, this represents a 32% decrease in the area requiring treatment!
Education & Outreach
• 1080 people reached via trainings, events, and workshops
• 81 homeowners received invasive weed consultations
• 6,200+ brochures distributed
Basin wide Invasive weeds reproduce prolifically by seed and root, and outcompete native and other desirable plants.
Once established, weed infestations:
• Reduce land and recreational values
• Damage water quality and clarity
• Contribute to soil erosion
• Degrade wildlife habitat
PRIORITY WEEDS
Group 1::
Watch for, report, and eradicate immediately.
These species are: 1) not currently found in the Lake Tahoe basin OR 2) documented in areas adjacent to the basin and may move into the area OR 3) are small, eradicable populations. Aggressive treatment will be pursued when these species are found; educational programs will target early detection and reporting of these species
Canada thistle (Cirsium arvense)
Diffuse knapweed (Centaurea diffusa)
Hoary cress (Cardaria draba)
Musk thistle (Carduus nutans)
Rush skeletonweed (Chondrilla juncea)
Russian knapweed (Centaurea repens)
Scotch thistle (Onopordum acanthium)
Squarrose knapweed (Centaurea virgata Lam. ssp. squarrosa)
Sulfur cinquefoil (Potentilla recta)
Teasel (Dipsacus fullonum)
Yellow starthistle (Centaurea solstitialis)
Group 2::
Manage infestations with a goal of eradication.
Encourage the management/control of populations of these species to prevent further spread in the Lake Tahoe basin. Isolated populations will be targeted for eradication.
Bull thistle (Cirsium vulgare)
Dalmatian toadflax (Linaria dalmatica)
Eurasian watermilfoil (Myriophyllum spicatum)
Curlyleaf pondweed (Potamogeton crispus)
Oxeye daisy (Chrysanthemum leucanthemum)
Perennial pepperweed (Lepidium latifolium)
Klamathweed (Hypericum perforatum)
Scotch broom (Cytisus scoparius)
Spotted knapweed (Centaurea biebersteinii)
Yellow toadflax (Linaria vulgaris)
The 2007 Annual Report will be available at the UCCE website: http://ucce.ucdavis.edu/counties/ceeldorado/.
