Restoring native vegetation along the North Fork Nooksack River, the Lummi Nation faces an unlikely adversary: nature.
The tribe has planted a streamside buffer near Bells Creek, where invasive knotweed, elk and beavers threaten the survival of the freshly planted trees.
Last year, Lummi Natural Resources placed large pieces of wood in Bells Creek to create protected pools for spawning coho salmon, steelhead and bull trout. A history of removing wood and straightening the channel for flood control had left the creek devoid of quality salmon habitat.
The next step was to plant trees in the 2-acre buffer along the creek near its confluence with the North Fork Nooksack River and within 17 acres of existing hardwood stands nearby. Whatcom Land Trust owns the property.
Conifers such as cedar, fir and spruce are essential for healthy salmon spawning and rearing habitat. Trees provide shade that cools the water, keeping it at an ideal temperature for fish. Over time, wood falls into the stream and further enriches the habitat.
However, invasive Japanese knotweed spreads rapidly and takes over river banks, impeding the growth of native plants. Mechanical removal encourages spreading. Herbicidal methods require multiple treatments and aren’t always effective.
“When we first came out here, we didn’t realize we had as much knotweed as we did,” said Frank Bob, Lummi tribal member and habitat restoration assistant. “We originally planned to just plant around the outer edges of the knotweed, but since we had so much of it, we decided to plant trees in the open space between the knotweed.”
To keep knotweed from blocking the sun and crowding out the young trees, Lummi crews are stomping the stalks to bend them back.
“It doesn’t kill it,” Bob said. “All we can do is buy the trees time to grow taller than the knotweed.” As with herbicide, this method will require continued maintenance and Lummi Nation only has funding to maintain the area for two years after planting.
Bob plans to enlist volunteer groups to help.
“We definitely can get people out here to stomp knotweed,” said Lindsay Taylor, volunteer coordinator for the Nooksack Salmon Enhancement Association. “Especially younger student groups — kids love to destroy stuff.”
With the knotweed out of the way, young cedars still are vulnerable to nibbling from elk and beavers. Spruce trees apparently are less appealing to elk than cedar, so the tribe planted sitka spruce alongside the cedars. Once the cedar is no longer vulnerable to browsing, tribal staff will cut back the spruce. If the cedar dies, the spruce will continue to grow.
The tribe is discouraging beavers by wrapping protective wire cages around the trees.
“We lost about 300 trees before we put up the cages,” Bob said.
Additional funding comes from the state Salmon Recovery Funding Board and the Pacific Coast Salmon Treaty.
For more information, contact: Frank Bob, Lummi habitat restoration assistant, 360-384-2267 or [email protected]; Kari Neumeyer, NWIFC information officer, 360-424-8226 or [email protected].
