DESCRIPTION
The River Rock Reach site is located along the banks of the Methow River 7 miles north of Twisp. Prior to 2009 the landowner set out to re-vegetate the 14 acre riparian property with native trees and shrubs. Since 2009, 1000 plants have been added to what was previously planted. Current stocking levels exceed 1300 plants. The long term goals of this project are to improve anadromous fish habitat and water quality by providing riparian shade, increasing large woody debris potential and improving bank stabilization. In the long term, this riparian planting will also enhance habitat values for other wildlife species and reduce invasive and noxious weeds and provide a seed source for future natural release of native trees and shrubs throughout riparian habitat conservation zone. Soils on the project are classified as fine sandy loam. The riverbank is composed of a mix of vegetation. The center of the property is a 3 acre cottonwood forest. To the north and south are planting zones currently dominated by non-native species, a mix of pasture grasses, smooth brome, diffuse knapweed, Canada thistle, cheat grass, and native grasses. The nature of the soils and vegetation types present challenges for establishing native vegetation. Sections of the bank along these zones are actively eroding and need vegetation to prevent further erosion. The opposite bank is similarly vegetated with a mix of cottonwood and pine.
The planting plan for the zones needing vegetation was modeled after the mature forest that exists at the north end of the property and the maturing forest in the center of the property. 200 native trees and shrubs were added to the existing restoration zone at the north end of the project. One area on the site has extensive rodent populations that have decimated plantings. In these areas we have planted species that recolonize via their roots. Due to sandy soils and inconsistent ditch irrigation it has been difficult to establish vegetation on this site. Other factors contributing to plant fatality include severe winter conditions, rodent population booms, and low rainfall. However, this site has established plants that are free from irrigation and are reproducing. Some enclosure fences have been removed, and the smallest plants protected with individual cages. Irrigation was stopped on all but newly planted stems after the 2011 season, as the site no longer needed that supplementation. The maintenance activities included monthly mowing, pulling of aggressive grasses, and application of fertile mulch. With re-planting, survival at the site is 100%.