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2010 "Volunteers Working With Invasives"
Grants Report Form

Display Report


Project Title: Community-Based Invasive Plant Management on Marin Islands NWR
Region: 8
Station: Marin Islands NWR
Contact Person:
Name and Phone Number
Giselle Block
Project Description:
(Up to 250 words)
The Marin Islands National Wildlife refuge (refuge) was established in 1993 to protect and enhance wildlife and associated habitats. The refuge supports the second largest heron and egret rookery in the San Francisco Bay region (>300pairs). Vegetation of the refuge is dominated by non-native trees, shrubs, and grasses and they continue to spread into native vegetation communities. A vegetation management plan (plan) for the refuge was developed in 2005 to guide control of invasive species and restore native plant populations. The goal of this project was to continue and expand implementation of the plan on the 10-acre East Island. Specific objectives of this project were to: 1. Monitor invasive and native plant cover in 2009 and spring 2010 treatment areas (Oxalis pes-caprae, Acacia) using GPS and the refuge spatial database. 2. Chemically remove remaining Oxalis populations (previously controlled in 2009) 3. Remove at least 80% of Acacia (4 species) shrubs and trees using mechanical and chemical control methods. 4. Transport Acacia off the island to a green recycling facility. 5. Reduce cover of Vicia sativa by 80% using mechanical and chemical control methods. 6. Track treatment efforts using the refuge spatial database. 7. Plant native grass in Oxalis treatment areas (Nassella pulchra, Nassella lepida) 8. Prepare report summarizing findings
List of Invasives Species Targeted:Common NameScientific Name
  black acacia Acacia melanoxylon
common vetch Vicia sativa
Bermuda buttercup Oxalis pes-caprae
Project Status: InProgress
Project Completion Date
or Estimated Completion Date:


Volunteer Affiliation:
(Check all that apply)
VA_FriendsGrp                                 VA_Other
Volunteer Involvement:
Describe the type of work the volunteers performed. (Up to 150 words)
Volunteer Involvement: Refuge staff trained 3 volunteers to identify and map priority invasive species prior to treatment in 2010. Volunteers mechanically removed all acacia trees (< 1’ dbh) from March through May 2010. Mechanical removal was immediately followed by chemical application of glyphosate to exposed trunks (conducted by permitted refuge staff) to eliminate re-sprouting. Downed trees were stacked and removed during a volunteer event ? 2010. Cooper Crane and Rigging transported a green recycling dumpster to and from the island for plant debris removal by volunteers. Common vetch was mechanically treated (mowed) by volunteers in late spring 2010, prior to seed set.
Total Number of Volunteers: 21
Total Number of Volunteer Hours: 336
List both new and existing partnerships utilized in this project. (Up to 150 words).
Friends of San Pablo Bay NWR, The Bay Institute, Bay Area Sea Kayakers


Project Results:
Give an overview of the results of the project. Include quantifiable measure of success, such as maps produced, efficacy of control measures, number of sites where invasions were detected early and responded to, number of community contacts, etc. (Up to 250 words).
Distribution and cover of priority invasive plants were determined using GPS and an invasive plant data dictionary. Maps of acacia, oxalis, and other invasive species were produced and guided treatment (mechanical and chemical). Over 95% of acacia trees were removed. Remaining trees (> than 1’ dbh) will be girdled in 2011. Eradication of acacia is expected in 2011. Oxalis treatment in 2010 represents 2nd year treatment of some patches and 1st year treatment of others. Follow-up treatment of this species is needed in 2011 for eradication. Eradication of Oxalis is possible within a relatively short time frame (e.g., < 5yrs). Oxalis represents currently represents the greatest threat to native grasslands of the Marin Islands, forming monocultures as it spreads. First year treatment of common vetch began in 2010 using mowing and removal of cuttings to reduce seed set and nitrification of soils.
Number of Acres Treated: 10
Number of Acres Inventoried and/or Mapped: 10
Number of Acres Restored: 10


Budget: Account for funds in broad categories such as equipment, volunteer stipends, travel, coordinator salary/contract, etc.

Total Grant Amount:

$ 12,600

Breakdown of Expenditures:


Total $ Spent
% of Total Grant
Equipment / Supplies 8,000 63
Biocontrol Agents
Volunteer Stipends 4,600 37
Volunteer Coordinator Salary/Contract
Restoration Materials
TOTAL 12,600 100

Recommendations: (OPTIONAL)
How useful was this program for meeting refuge invasive species objectives and how can it be improved?
This funding mechanism provides much needed assistance with control and eradication of priority invasive species on refuges.


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