Integrated Weed Management Plan

Case studies of current practices on BCPOS lands

Boulder County Parks & Open Space (BCPOS) is working to update the Integrated Weed Management Plan for Boulder County. This Story Map serves as a companion to the draft plan. The Story Map provides some important planning context. The Story Map also provides some case studies of lands where Integrated Weed Management has already been implemented by BCPOS.

Feedback on the draft of the plan document is currently being sought. Survey found here:  https://bouldercounty.gov/open-space/management/weeds/#planupdate 

The Management Objective and Strategies of the plan are shown at right.

Under State law, BCPOS is required to manage noxious weeds. BCPOS strives to eradicate weeds on List A due their limited population size by consistent scouting and taking measures to prevent reproduction. BCPOS strives to contain weeds on List B and keep them from spreading. Weeds on List C are much more prevalent, we strive to suppress weeds on List C as there tends to be no economical alternative. BCPOS uses an "Early Detection/Rapid Response" approach to our management to most effectively comply with State law. In addition to the compliance measures, BCPOS strives to concurrently improve ecosystem health on open space lands using a variety of management tools using an integrated approach.

BCPOS protects about 115,000 acres of land. About 49,500 are managed by the department for natural resource preservation with compatible recreation where weed management is the responsibility of BCPOS. The remaining lands are either leased to agricultural tenants (about 26,000 acres) or are private lands protected by conservation easements (about 36,500 acres).

The 49,500 acres of lands managed directly by BCPOS is about the size of Longmont, Boulder, Louisville, Lafayette, and Superior combined, a bit more than 77 square miles or about 10.5% of Boulder County.

Striving to comply with State law while also seeking to improve ecosystem health takes significant effort and a strategic approach.

Many of these lands were acquired by BCPOS in order to preserve the high natural resource values. These values are mapped in the Environmental Resource Element of the Boulder County Comprehensive Plan. Maps of High Biodiversity Areas, Critical Wildlife Habitats, and Preble's Meadow Jumping Mouse are shown here. Integrated Weed Management is an important land management tool for protecting the high value natural resource areas identified on these maps from the negative impacts of invasive weeds.

This is the High Biodiversity Areas map with the green areas having the highest degree of biodiversity with significance on the global scale.

This is the Critical Wildlife Habitats map. Purple areas are critical for sustaining populations of Boulder County's native species.

These are Habitat Conservation Areas for the Preble's meadow jumping mouse. Preble's is a federally-listed threatened species. Yellow areas are designated as "Mouse Management Areas" where populations of mice are known to exist.

Our Adaptive Integrate Weed Management Decision Model illustrates our adaptive planning and decision-making process for implementing management at any given location. As the model demonstrates, it functions as a feedback loop where our treatment approach is evaluated treatment-by-treatment to ensure we are in alignment with the IWMP's overall objective.

In the model, we initially establish management objectives based on legal requirements and the open space values. Then, we conduct the designed treatments and monitor/evaluate effectiveness. The resulting data informs any subsequent treatment or other actions. The case studies that follow illustrate this process at specific locations.

CASE STUDIES - MAP TOUR

Pella Ponds - Crane Hollow

The west side of Pella Ponds between Crane Hollow Road and St. Vrain Creek is important habitat for federally-listed Preble's meadow jumping mouse. In 2019, the area was infested with Canada Thistle and Teasel. Staff have worked to steadily decrease weed populations incrementally since then by simultaneously expanding the treatment area and decreasing the amount of area being treated with herbicide in combination with mowing.

Rabbit Mountain

Ron Stewart Preserve at Rabbit Mountain is one of only two globally significant biodiversity areas in Boulder County. BCPOS is taking an integrated approach to resetting the native ecosystems there that have been impaired by infestations of cheatgrass. Using one-time treatments of an herbicide called Rejuvra, the diversity and vitality of native plants in this unique ecosystem is transforming.

Monarch Open Space

Monarch Open Space was highly infested with noxious weeds and denuded. Beginning in 2020, an Integrated Weed Management approach was taken to reestablish native vegetation and control invasives. Tools used included mechanical treatment (mowing), cultural (revegetaion), and herbicides treatment. As of 2023, much of the land has been rehabilitated and herbicide use has been greatly reduced (down from 50 acres to 10 acres).

Williams-Merlin Open Space

After a patch cut was made in this Lodgepole pine stand on county open space along Peak-to-Peak Highway, it was experimentally replanted with seed of Limber pine, a rare plant in Boulder County. The objectives of the revegetation effort are to increase forest diversity and establish a seed source for use at other locations. Canada Thistle and Mullen are also taking advantage of the recent disturbance. A combination of spot herbicide treatments and hand work are being used to protect the young seedlings while controlling the infestation. Herbicide use is decreasing over time.

Pella Ponds - Crane Hollow

The west side of Pella Ponds between Crane Hollow Road and St. Vrain Creek is important habitat for federally-listed Preble's meadow jumping mouse. In 2019, the area was infested with Canada Thistle and Teasel. Staff have worked to steadily decrease weed populations incrementally since then by simultaneously expanding the treatment area and decreasing the amount of area being treated with herbicide in combination with mowing.

Rabbit Mountain

Ron Stewart Preserve at Rabbit Mountain is one of only two globally significant biodiversity areas in Boulder County. BCPOS is taking an integrated approach to resetting the native ecosystems there that have been impaired by infestations of cheatgrass. Using one-time treatments of an herbicide called Rejuvra, the diversity and vitality of native plants in this unique ecosystem is transforming.

Monarch Open Space

Monarch Open Space was highly infested with noxious weeds and denuded. Beginning in 2020, an Integrated Weed Management approach was taken to reestablish native vegetation and control invasives. Tools used included mechanical treatment (mowing), cultural (revegetaion), and herbicides treatment. As of 2023, much of the land has been rehabilitated and herbicide use has been greatly reduced (down from 50 acres to 10 acres).

Williams-Merlin Open Space

After a patch cut was made in this Lodgepole pine stand on county open space along Peak-to-Peak Highway, it was experimentally replanted with seed of Limber pine, a rare plant in Boulder County. The objectives of the revegetation effort are to increase forest diversity and establish a seed source for use at other locations. Canada Thistle and Mullen are also taking advantage of the recent disturbance. A combination of spot herbicide treatments and hand work are being used to protect the young seedlings while controlling the infestation. Herbicide use is decreasing over time.