By Natasha Coumou, assistant restoration ecologist with the Tulalip Tribes
Invasive plants can increase wildfire risk in urban areas and pose a threat to fish and wildlife habitat, including salmon streams and forests.
That’s why the Tulalip Tribes’ Natural Resources Department, a Puget Sound Corps crew, and the Washington State Department of Natural Resources (DNR) joined forces earlier this year to remove scotch broom, poison hemlock, invasive blackberry, and reed canary grass in parts of Snohomish County – including on the Tulalip Reservation. In February and early March, crews reduced and removed these invasive species on approximately 5 acres of land and a 1-mile stretch of urban trail.
DNR funded the Puget Sound Corps’ work on this Tulalip-led project. The Puget Sound Corps is a multi-agency effort and part of the broader Washington Conservation Corps (WCC) program overseen by the state’s Department of Ecology. The WCC – an AmeriCorps program – creates future leaders through community involvement and mentorship and has more than 350 members and experienced staff statewide who restore critical habitat, build trails and respond to local and national disasters.
Here is what this one crew was able to accomplish for the Tulalip Tribes in parts of Snohomish County:
Scotch broom removal
Scotch broom is prevalent in Snohomish County and a potential fire hazard that can increase the intensity of grassland and forest fires. On the Tulalip Reservation, scotch broom has dispersed throughout urban forests, trails and public areas.
Seeds of the scotch broom plant can remain viable for several decades. The Puget Sound Corps crew temporarily increased the tribes’ capacity to deal with scotch broom in areas that have a great potential to further disperse its seeds and exponentially increase its presence elsewhere.
One of these areas is the forestry wood yard, where the Tulalip’s natural resources staff temporarily store firewood that it redistributes throughout the community. Scotch broom there creates a continuous ground fuel by establishing itself between woodpiles, and its seeds are easily transported to other areas of the reservation. There, the crew cleared about a 1-acre area by mechanical removal.
Another area where scotch broom has invaded is the Qwuloolt Estuary in the city of Marysville, which is adjacent to a residential area. Besides the increased fire risk, the water can carry scotch broom seeds to other areas in the Snohomish River Estuary. The acre of scotch broom removal also freed up habitat for native trees and plants that support healthy salmon populations known to inhabit the Qwuloolt, including Chinook salmon, the primary food source for Puget Sound southern resident orcas.
Poison hemlock removal
Poison hemlock is a non-native invasive plant that can be fatal if ingested by humans and many animals, and it is prevalent in disturbed areas, such as trails throughout the region that are frequently visited by the public. One of the most frequented public trails by the Tulalip’s health clinic has been overrun by this plant and pose an immediate danger to families using the trail.
The Puget Sound Corps crew cleared extensive patches adjacent to the trail to reduce poison hemlock density, and to decrease the immediate risk to the public of encountering this plant. During their time, the crew manually removed, filled and disposed of more than 30 large (about 100-gallon) trash bags of poison hemlock, reducing fire hazard and the risk of public exposure to this toxic plant.
Reed canary grass management
The crew also removed reed canary grass from a restoration site that was established on the Qwuloolt Estuary. In an effort to restore a resilient landscape, the Tulalip Tribes planted native evergreen trees (shore pine and sitka spruce) to outcompete the invasive grass, which had taken over a contiguous swath of land.
The grass posed an increased fire risk by creating uninterrupted horizontal fuel in an area adjacent to residential housing. To reduce its prevalence and help the establishment of a hardy, fire resilient urban landscape, the crew mowed about 3 acres of reed canary grass.
During their time with the Tulalip Tribes, the Puget Sound Crew members removed non-native blackberry and scotch broom from a forested buffer on the banks of the Skykomish River in Monroe. The Tulalip Tribes are in the process of acquiring this area from the PCC Farmland Trust to put it in perpetual conservation.
A riparian forested buffer adjacent to the river was established decades ago to enhance habitat and water quality for salmon and other species, and the mature forest is a testament to the project’s success. Where younger maturing forests exist, however, woody invasive species like blackberry and scotch broom are competing with beneficial native vegetation.
To maintain a healthy forest, invasive species management is paramount. The crew cleared an acre of the buffer of blackberry and scotch broom, allowing for a more resilient landscape. While working on this project, members also cleared a trail that was overgrown with vegetation to provide access to a future restoration area.
The collaboration between DNR, the Puget Sound Corps and the tribes significantly expanded the capacity of the Tulalip’s Natural Resources Department to remove invasive species on and off the reservation, benefiting communities, the watershed and urban forests.