The 4-County CWMA

Cooperative Weed Management in Oregon & Washington

The Clackamas / Clark / Multnomah / Washington County Cooperative Weed Management Area (4-County CWMA) is a partnership of organizations, agencies and non-profits dedicated to combating invasive weeds across the region. Member organizations have committed to these efforts for a variety of reasons: supporting agricultural production, protecting human health, and preserving air, water and soil quality.

Those reasons are often locally based: cities and farms worry about and deal with invasive species differently. In a related way, the range of habitats in the Lower Willamette Valley plays a role in dictating which species are invading, and how problematic they are. So, the diversity of the landscape is a crucial consideration around here, leading to a wide range of management activities and strategies.

And, of course, invasive species don’t care about boundaries. So collaboration across jurisdictions is critical. Besides keeping treatments consistent across boundaries, partnerships can sometimes give rise to new sources of funding, and make for more efficient projects.

All of this informs our website. We talk to a lot of different people in a lot of different situations. We want our website to reflect that range. If you feel otherwise, or can’t find what you’re looking for, we want to know that. We’re aiming for ‘perfect’ but we’re not quite there, yet…

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Get involved!

Check out our annual Pull Together event, and learn more about educational opportunities from the 4-County CWMA and our partners.

Educational Opportunities

Invasive Species Resources

Invasive species are typically introduced plants, animals and insects that threaten the ecosystem by outcompeting native species for resources such as space, light, food and water. These resources provide information to assist users in identifying and managing invasive species based on proven Integrated Pest Management (IPM) practices.

Priority Weed Coordination

The invasive species detected within the 4-County CWMA region vary in their abundance, distribution, and impact. Priority weed coordination identifies the species that are the most invasive, and where eradication is possible.

Without priority weed coordination, chances of eradication are lost. This leads to habitat degradation, decreased economic productivity, and increased strain on the management of other invasive species. The CWMA accomplishes priority weed coordination through collecting and sharing up-to-date invasive species data.

Data Collection

Effective invasive species management requires accurate records of species presence and control efforts.

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Data Sharing

The data your organization collects has an important role to play in the utility of collective databases.

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Support the CWMA

There are many ways that you can help stop the spread of invasive weeds in your area. Whether you’re a resident, a property manager, an educator, or someone looking for volunteer opportunities, there’s a way for you to take part in protecting native plants and habitats.

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