Start receiving our award-winning magazine today!



Taking the Field Against Green Invaders

Invasive species are an increasingly grave threat to healthy ecosystems. The Nature Conservancy is working across Oregon and beyond to conserve important lands and waters from threats posed by these problematic plants.

Cox Island Preserve

Cox Island, on Oregon's central coast, is an excellent example of an estuarine saltmarsh ecosystem.

The island, however, has the unfortunate distinction of having the only known Oregon population of saltmeadow cordgrass, Spartina patens — an invasive, introduced species that threatens native wetland vegetation. Researchers believe it arrived decades ago in packing material for clams, and Conservancy ecologists and volunteers are working to control the species and prevent it from spreading to other coastal marshlands.

One simple method proved highly successful: With help from volunteers, cover the invasive patches with landscaping fabric and leave it there for two years. Conservancy studies on Cox Island showed that Spartina was completely killed and, within a year of removing the fabric, native vegetation returned. examples:

Sandy River Gorge Preserve

In the Sandy River Gorge, six miles of untamed river with upland terraces and canyons provide excellent habitat for native fish, wildlife and an old-growth forest, all within 20 miles of Oregon's largest urban area.

After flooding along the Sandy River in the 1990s, however, an invasive ornamental called Japanese knotweed took root and quickly exploded onto riverbanks. The plant, left untreated, grows at alarming rates, dwarfing other vegetation and displacing extensive native streamside habitats.

Ecologists and volunteers have been working with hundreds of private landowners and other partners to successfully remove the invader and save miles of riparian habitat crucial to native plants and animals, including wild salmon.

Zumwalt Prairie Preserve

Field research at Zumwalt Prairie Preserve in Eastern Oregon isn’t always done with notepads and paper. Albeit romantic, such note-taking can be slow and cumbersome to translate for conservation analysis and planning. 

Powerful new technology now allows a global positioning receiver to link data and satellite images to a researcher’s palmtop computer screen.

On the preserve, invasive cheatgrass threatens the native bunchgrass prairie. Conservancy researchers working to map invasive species and apply treatments now build extensive aerial maps and enter on-the-ground data directly into the recorder, saving time and, most importantly, habitats too.

These are just a few examples of what The Nature Conservancy is doing to abate the threat of invasive species in Oregon. For more information about these or other projects, or to find out how you can help, please call us at (503) 802-8100 or e-mail

We’re Accountable

The Nature Conservancy makes careful use of your support.

More Ratings

x animal

Sign up for Nature eNews!

Sign Up for Nature e-News

Get our e-newsletter filled with eco-tips and info on the places you care about most.

Thank you for joining our online community!

We’ll be in touch soon with more Nature Conservancy news, updates and exciting stories.

Please leave this field empty

We respect your privacy. The Nature Conservancy will not sell, rent or exchange your e-mail address. Read our full privacy policy for more information. By submitting this form, you agree to the terms of use.