Wildfires that tortured the Pacific Northwest in September did a number on the Washington Department of Fish and Wildlife’s (WDFW) Swanson Lakes Wildlife Area (Swanson Lakes), located about 10 miles south of the town of Creston.
Swanson Lakes is a 21,000-acre tract of native grasslands nestled among the channeled scablands of the Columbia Plateau. Shrub-steppe and riparian/wetlands comprise the dominant habitats and much of the area is rangeland, with some old Conservation Reserve Program fields. The undulating landscape is characterized by numerous pothole and rim rock lakes and one intermittent stream.
In western habitats, wildfire threatens native vegetation in two ways. First, given our rangeland’s generally unnatural fire cycles from fire management and encroaching invasive species, wildfires often burn much hotter than they would in pristine habitats. Fires that are too hot scorch the seed bank and possibly the underground root structure of native shrubs like sagebrush, damaging the plant’s potential to regenerate. Second, invasive weeds are incredibly prolific and competitive. In the case of the earth being blackened down to bare soil, weeds can quickly flourish, outcompeting native plants, often by simply covering the area, effectively shading out the native species.
Fortunately, WDFW was poised to respond, leveraging funds in cooperation with the Bureau of Land Management (BLM) to quickly apply native grass seed mix to the charred Swanson Lakes landscape. Aerial seed drops covered about 930 acres on October 22nd, scattering two varieties of bluebunch wheatgrass, Idaho fescue, Sandberg bluegrass, and prairie dune grass across Swanson Lakes and a portion of adjacent BLM lands, said Mike Finch, WDFW Swanson Lakes Wildlife Area Assistant Manager.
Fall is not the ideal season to sow grasses, but the timing could not have been better. The WDFW and BLM made the seed drops in October to ensure native seeds were available to germinate on the exposed soil ahead of any invasive species seeds. Additionally, wet snow that fell October 23rd and 24th worked well to soak the seed into the soil surface, increasing the likelihood of establishment through good seed-to-soil contact. The WDFW plans to return with machinery in drier conditions to scratch the seeds slightly deeper into the soil surface.
Finch mentioned that Swanson Lakes was one of three areas receiving fall seed drops. The areas were prioritized for immediate reseeding due to their deeper soils, being more likely to establish and sustain healthy native grasses by allowing roots to grow down into moist soils for good summer survival. Understanding site conditions and prioritizing restoration efforts is important for project success and the best use of resources, particularly with the cost of native grass seed as high as $200 per acre, plus application time.
Native shrub-steppe communities are a critical part of the ecosystem in the arid west, providing food and shelter for a wide variety of wildlife. The sharp-tailed grouse, for example, is an iconic western prairie grouse species that thrives in shrub-steppe habitat. Precisely why maintaining quality native habitat in Swanson Lakes is of critical importance. The area was acquired by the Bonneville Power Administration, primarily as a wildlife mitigation project for Columbian sharp-tailed grouse, a state “threatened” species.
By leveraging funding and relationships with the BLM, and making smart decisions on the use of available resources, WDFW can sustain unique and important shrub-steppe habitat areas like Swanson Lakes to benefit wildlife and the public user well into the future.