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2006 "Volunteers Working With Invasives"
Grants Report Form

Display Report


Project Title: Invasive Knotweed Surveys and Control in Ridgefield Complex Refuges - Ridgefield and Steigerwald Lake NWRs
Region: 1
Station: Ridgefield NWR Complex
Contact Person:
Name and Phone Number
Jim Clapp, (360) 835-8767
Project Description:
(Up to 250 words)
Early detection and treatment is crucial for successful, cost-effective control of Japanese, giant, and Bohemian knotweed. This riparian weed has become a serious problem along several streams/rivers in Clark County, and was discovered about 5 years ago in several locations on the Ridgefield Complex Refuges along the Columbia River. We have treated them annually where easily observed, but not had the time to do an extensive survey of the waterways along which this plant could occur. This project will provide a coordinator and volunteers to conduct surveys along approximately 17 miles of creek, river and lake shoreline to locate, identify location by GPS coordinates, and prepare a report of their findings.
List of Invasives Species Targeted:Common NameScientific Name
  Japanese Knotweed Polygonum cuspidatum
Giant Knotweed Polygonum sachalinense
Himalayan Knotweed Polygonum polystachum
Project Status: Completed
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)
Refuge volunteers, working with a volunteer coordinator/work leader, mapped knotweed species at Ridgefield, Steigerwald Lake, Franz Lake, and Pierce NWRs. Work was conducted under summer field conditions (July and August) along waterways dominated by up to 8' tall reed canarygrass, making travel difficult. When located, plant locations were identified using GPS and GIS technology and included in a report completed by the volunteer coordinator.
Total Number of Volunteers: 5
Total Number of Volunteer Hours: 120
List both new and existing partnerships utilized in this project. (Up to 150 words).
Volunteers were recruited from the database of Friends of Ridgefield National Wildlife Refuge, an existing Friends group for over 10 years. Refuge staff continues to work with personnel of the Clark and Skamania County Weed Boards to identify and treat noxious weeds, and has been successful in encouraging County control of knotweed control upstream of refuge inputs where possible.


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).
Survey results indicated Japanese knotweed found on three of the four refuges surveyed - Pierce, Ridgefield and Steigerwald Lake. No Himalayan or giant knotweed was identified on any of the four refuges. Intensity of the on-refuge infestations was greatest immediately downstream of the refuge boundary, and decreased with distance from that boundary. After the survey was completed, a contractor was hired with refuge funding to treat the all of the knotweed located during the month of September 2005. Subsequent surveys and treatment of remaining knotweed were conducted during summer 2006 by Skamania County on Pierce (Skamania County Weed Board) and Steigerwald Lake (Skamania County Weed Board employee recruited as a volunteer) Refuges. As of September 2006, approximately 95 percent of the knotweed located during the volunteer surveys of 2005 had been eliminated, and no new infestations were located.
Number of Acres Treated: 1
Number of Acres Inventoried and/or Mapped: 15
Number of Acres Restored:


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

Total Grant Amount:

$ 5,650

Breakdown of Expenditures:


Total $ Spent
% of Total Grant
Equipment / Supplies 1,851 33
Chemical 1,300 23
Biocontrol Agents 0 0
Travel 0 0
Volunteer Stipends 0 0
Volunteer Coordinator Salary/Contract 2,499 44
Restoration Materials 0 0
TOTAL $5,650.00 100

Recommendations: (OPTIONAL)
How useful was this program for meeting refuge invasive species objectives and how can it be improved?
The funding for this program was extremely helpful in getting our intial survey of knotweed accomplished, with followup treatment and additional surveys done by refuge staff and a partnering County Weed Board.


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