Emergent vegetation mats are in the ground!

Reed canary grass (Phalaris arundinaceae) has invaded thousands of acres of wetland habitat in the Pacific Northwest, degrading or destroying habitat for the Oregon spotted frog (Rana pretiosa), a federally threatened species. Successful restoration of invaded areas generally requires replacement with native plants, typically woody trees and shrubs. However, to restore oviposition habitat for Oregon spotted frog, we need to replant with low-stature herbaceous species, which can be extremely difficult in wetland areas with dynamic hydrological regimes.

To overcome this challenge and to restore native rushes and sedges, we have installed emergent vegetation mats, biodegradable coconut coir mats pre-planted with native species, into wetland restoration plots. The pre-planted mats have excellent root development and they allow little to no light penetration, helping to quickly establish the native plants and limit re-growth of reed canary grass into treated areas.

Root development on the underside of vegetation mats.

We installed nine 3m x 3m emergent vegetation mats at each of three sites: West Rocky Prairie, Mima Creek Preserve, and Watkins Marsh at Joint Base Lewis-McChord.

Installing mats at West Rocky Prairie.

Installing mats at JBLM.

In collaboration with Sustainability in Prisons Project, Joint Base Lewis-McChord, Washington Fish and Wildlife, and the U.S. Fish and Wildlife Service, we will continue to monitor the success of this new method for both wetland plant establishment and creation of Oregon spotted frog oviposition habitat.

Installation team at West Rocky Prairie.