A key component of the Cheasty Greenspace Trails and Bike Park project is restoring the northern 33 acres of Cheasty Greenspace.
What is restoration?
Ecological restoration is an intentional activity that starts or accelerates the recovery of the health, integrity, and sustainability of an ecosystem. An ecosystem may require restoration because it has been degraded or damaged as a result of human activity. The degradation may be so severe that the ecosystem cannot recover its predisturbance state or its historic developmental trajectory without assistance. The goal of restoration is to return an ecosystem to its historic trajectory.
Many of Seattle’s forests are in need of restoration because of severe degradation due to logging and development combined with the influx of invasive (aka exotic) species. After logging of this area in the late 1800′s and early 1900′s, much of the area we now call Cheasty Greenspace was gradually infiltrated with invasive plants like English Ivy and Himalayan Blackberry. These hardy invasives have choked out native understory that would have provided habitat as well as the basis for the forest’s natural regeneration. They have also prevented the growth of late-succession species like Western Hemlock and Western Red Cedar, species critical to a healthy Western Washington forest.
Indeed, city foresters have labeled this area a “Triage Stage 6,” (with a 1 representing a healthy native forest and 9 designating the worst possible conditions.). In 2003, these city foresters created a Vegetative Management Plan that found 48% of Cheasty Greenspace had more than 75% coverage by invasive plants (mostly ivy and blackberry) and that 63% of seedlings were non-native. In addition illegal encampments and garbage dumps were found throughout the greenspace and continue to pop up today.
Despite the influx of invasives, a moderate amount of native plants continue to persist under the invasive cover, and volunteer efforts are increasing to provide full restoration of this native forest!
Our restoration efforts include:
- Removing invasive plants by hand, which allows us to remove invasive species root systems and protect the existing native understory. Removal will be focused on ivy and blackberry, particularly in the beginning stages of this project. For a longer list of invasive plants infiltrating the forest, visit the Green Seattle Partnership target weed list and the reference map.
- Composting invasive plants on-site, raised above the soil on “rafts” made out of fallen wood, which helps keep emerging shoots from setting back into the soil. Eventually these compost mounds will be dispersed back into the forest, providing nutrients for future native plant growth.
- Planting native plants. A significant portion of the budget for this project provides for purchase of the many thousands of native plants we will need to fully restore this 33 acres. Planting is dictated by the season, so young plants can build a robust root system before the dry summer.
- Mulching native plants and open areas with wood chips will help maintain moisture in the soil, supporting root growth and soil tilth. As the mulch breaks down it will add nutrients to the soil supporting plant growth into the future.
- Maintenance. Deep roots and durable seeds of invasive plants will continue to be a challenge in this forest and volunteers will continue restoration work long after the initial phase of this project is complete. As native plants grow to fill the space, and invasives continue to be removed, restoration needs will decrease, but the citizens of South Seattle will continue to come together to maintain this native forest.
To learn more about restoration in general, see the Society for Ecological Restoration’s International Primer on Ecological Restoration.