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Integrated Pest Management methods for Invasive Plant Control (Programmatic CE - 2022-2026)

Lewis and Clark National Historic Park » Integrated Pest Management methods for Invasive Plant Control (Programmatic CE - 2022-2026) » Document List

From 2022 to 2026, Lewis and Clark NHP proposes conducting invasive plant control using the principals of Integrated Pest Management (IPM). IPM protects resources from invasive species while reducing risks to people and the environment by utilizing the least harmful, yet effective methods of control possible for any given species. The Park will employ an IPM approach of techniques and treatments that include manual and mechanical (hand-pulling, weed whips, brush cutters, and mowing), cultural (timing of treatment and restoration), planting of native species, and limited herbicide treatments when warranted.

Through direct experience, research, technical assistance from NPS Invasive Plant Program (IPP), and referring to Best Management Practice (BMP) guidance, the proper control prescription is determined. For major infestations, treatment strategies and application are coordinated with North Coast Cascade Network Invasive Plant Management Team (NCCN IPMT).

Manual (pulling, cutting, digging) or Mechanical (weed whacking, mowing, sawing) methods are used whenever possible.

Hand pulling and use of a weed wrench will be limited to areas outside of the boundaries of known archeological sites and Resources staff will coordinate with the Park archeologist prior to work.

When these prove ineffective, targeted herbicide use is employed. For difficult to kill species such as Himalayan and cutleaf blackberries, scotch broom, cotoneaster, and gorse, a cut-stump treatment method is used, wherein a small amount of liquid herbicide is applied directly to the freshly cut stem surface. For species like yellow iris where cut-stump treatment isn't feasible, herbicide is applied directly to the plant, as a foliar treatment, with a backpack sprayer. For woody species like holly and English laurel, the EZ-Ject lance system, which utilizes herbicide encased in capsules, is used.

Any areas treated with herbicides will be flagged and signed for identification. The area will be closed as needed in accordance with herbicide lable directions following the applications.

All herbicides will be used in compliance with state and federal law and within label guidelines. All herbicide use is entered into the Pesticide Use Proposal system (PUPs) prior to use, and then the quantities applied are also entered into PUPs at the end of the season. Infestations and treatments are mapped using GIS and monitored for effectiveness.

Invasive plant control at Middle Village Station Camp is conducted with special consideration for the cultural resources of this important site. No ground disturbance is permitted within the natural ground surface at the site. Ground disturbance in elevated areas created during the park construction is permitted.

It is determined that this action can be documented under a Categorical Exclusion, in accordance with the National Environmental Policy Act (NEPA) and NPS policies. In addition, this project has been identified as an undertaking eligible for streamlined review under provisions of the National Historic Preservation Act (NHPA) and the Service wide programmatic agreement (2008). This programmatic CE will be reviewed annually. Projects would be implemented over five years from April 1, 2022 to December 30, 2026.