Save a Forest in Southworth, WA

Southworth Forest Update:

Native Understory Returning After Noxious Weed Removal

Posted April 22, 2023 by Southworth Forest

Western skunk cabbage is a flowering perennial plant that can grow up to a few feet tall in wetland conditions such as this stream through the Southworth Forest (2023)

Seven years into the forest restoration project at Southworth, WA, the native understory is increasingly returning. While planting native conifers and deciduous trees has been the priority goal after noxious weed removal, care for the understory continues at the same time. Garbage removal on the northern and western sides of the forest is key to this work as well.

The primary invasive species choking out the native understory include Himalayan blackberries, English ivy, Scotch broom, and English holly. They are being removed up to the buffers for the Category IV wetlands in the forest that are anchored by a non-fish bearing stream that has historically housed river otters. The Scotch broom and blackberries require ample sunlight, but the ivy and holly prevail in the shade of the forest.

Western sword ferns thrive throughout much of the forest even amongst the invasive species. They are struggling on the eastern side of the forest, though, where the deforestation of 11090 SE Southworth Dr. has left them exposed to burning from heat and infiltration by Scotch broom and bracken ferns. (View evidence of these impacts by careless landowners.) In these areas, only the long-term restoration of the forest canopy will ensure the sword ferns' habitat.

To celebrate Earth Day 2023, we cataloged a variety of native understory plant species making a comeback throughout the Southworth Forest. With the extremely wet and cool April weather has come a delayed but hopefully robust crop of huckleberries, salmonberries, Oregon grape, trillium, and a slew of other species no longer fighting the invasive species as before. Salal and several types of native roses take more time to return but are showing progress.

As of 2023, about a third of the forest's understory has been manually cleared of invasive species. This work will continue for many more years as the new tree canopy grows.

The deciduous red huckleberry shrub (above) is shown next to trillium (below). Note the English ivy underneath that required removal after this photo was taken. (2023)

We have the lower, "Cascade" version of the evergreen Oregon grape shrub that grows well amongst companion salal and western sword ferns. (2023)

Sprinkled amongst native blackberries species are salmonberries, a shrub with orange raspberry-like fruit that feature the flower shown here. (2023)

Per State Environmental Policy Act (SEPA) evaluation, the relevant WAC 197-11-444 elements for these noxious weed impacts are:

• (1) Natural environment > (d) Plants and animals > (i) Habitat for and numbers or diversity of species of plants, fish, or other wildlife
• (2) Built environment > (b) Land and shoreline use > (iv) Aesthetics