The King County Department of Natural Resources and Parks is conducting vegetation management control on more than 300 acres of county-owned forest sites to encourage the growth of young conifer trees.

The work, known as conifer release, is a type of weeding that land managers perform in young forests where there is too much shade and competition from undesirable vegetation. Some of the work will be done in March through May, and crews will return to the forests to complete the work in late summer.

As part of its forest stewardship program, King County has hired a contractor to complete the work at Ring Hill Forest, Taylor Mountain Forest, McGarvey Park Open Space and Black Diamond Open Space. These sites were harvested between 2007 and 2013, and replanted with more than 100,000 conifer seedlings.

There will be limited trail closures which will be indicated with signs at trailhead kiosks and intersections that lead into project areas.

Work on Ring Hill and Taylor Mountain Forests involves manually cutting non-native and invasive plants such as scotch broom, butterfly bush and blackberry. Crews will also thin stands of native trees that have naturally regenerated, such as red alder, cottonwood and maple, and that are crowding out the young planted conifers.

Removing selected deciduous trees reduces competition for sunlight, nutrients and water, and allows the young conifers to thrive and grow vigorously. All cut trees will be left on-site to decompose and return nutrients to the soil.

The invasive control and thinning of McGarvey Park and Black Diamond Open Space will be done with directed, spot application of herbicides. Trails within the project area will be closed during spray operations, and “trail closed” signs will be posted at all trailheads and intersections of all trails entering the project area.

Parks employees will re-open the trails and remove the signs within 24 to 48 hours of herbicide applications.

“Treating competing vegetation ensures young trees will survive and become healthy forests for generations to come,” said Bill Loeber, a forester with the King County Department of Natural Resources and Parks.

King County manages more than 28,000 acres of forests within 200 parks and open space sites across the county.

Through the county’s forest stewardship program, selected forest sites are harvested, thinned and replanted to promote forest health and biodiversity, protect wildlife habitat, and provide passive recreation on more than 200 miles of backcountry trails.

For more information, contact Loeber at 206-477-4755; or bill.loeber@kingcounty.gov.