Invasive Species Management at Mary S. Young State Park

Mary S. Young Park State Park is located in West Linn, Oregon, next to the Willamette River. It houses around 128 acres of biodiverse habitat, 5-8 acres of hiking trails, and is home to a variety of native and invasive species.

With the beauty of Mary S. Young State Park's trails comes the difficult task of invasive species management. Ongoing efforts are practiced to eradicate historically problematic regional invasive and undesirable species outbreaks at the park. Invasive species management at Mary S. Young State Park is imperative because of the park's location on the Willamette River. If invasions move beyond the park toward the fragile riparian habitat on the banks of the Willamette and beyond within the river basin system, invasions are significantly more likely to establish and cause greater ecological and economic harm.

Ongoing efforts to control and eradicate historically problematic invasive and undesirable species are underway through community efforts. Volunteers operate bi-weekly to remove invasive or undesirable species in the park along with partaking in trail restoration. SOLVE Oregon manages volunteer work parties which include education, species removal, and native species planting. Volunteers are a large part of park management, and effectively control many invasive species in the park. To maintain the native species of the park, mapping invasive species locations, volunteer education, and community outreach are goals for future invasive species management and eradication.

This StoryMap was created in the Fall of 2020 due to a need for efficient invasive species mapping in the west end of Mary S. Young Park. We developed this resource by hiking along the park's Heron Creek Loop trail and identifying invasive species outbreak sites along the trail using Google Maps. Scouting was done once a week for three weeks, with 2-hour long sessions of scouting.

This online resource was created in collaboration with Portland State University's Fall term Ecology & Management of Bio-invasions course, taught by Professor Catherine de Rivera, Ph.D. The Interactive Map allows for historical invasive species tracking and monitoring, and facilitates future spatial analysis and insights through mapping and community engagement.

To report new invasive species sightings and share spatial data, please email  marysyoungpark@gmail.com .

To volunteer for invasive species management, please contact our Volunteer Coordinator David Kleinke at (503) 799-1777 or  msypvolunteercoordinator@gmail.co m.

Visit our website for more information about Mary S. Young State Park:

Questions about this resource? Contact:

Kylee Church | Project Lead | Portland State University |  kychurch@pdx.edu 

Julian Roth | Project Lead | Portland State University  | julroth@pdx.edu 

Catherine de Rivera, Ph.D. | Professor | Portland State University |  derivera@pdx.edu 

Hints: Tap the symbols on the Interactive Map and reference the Legend below to identify invasive species outbreak sites. Use the 'Find my location' button (circular button on the lower right-hand corner of the map) while you're out on trails to see your proximity to the Fall 2020 outbreaks.

English Holly was found to be most invasive species at the park, and is an emergent threat to the native habitat around the Heron Creek Loop Trail. Seeded English Holly has been identified in the northwestern and southwestern regions of the park and will likely propagate over the next couple of years, further challenging eradication efforts. English Holly could potentially spread further via transport vector such as birds spreading seeds/berries and park visitors that spreading seeds on their shoes along trails.

English Holly poses a high risk of invasive habitat expansion within the Willamette River basin. The spread of English Holly to the banks of the Willamette would likely damage the essential and delicate riparian habitat along the river. Early eradication of areas where there have been English Holly sightings is recommended.

Visitors and volunteers can use this identification guide to cross-reference findings of common undesirable species during the Fall/Winter months while out on the trails.

Photos and subsequent information courtesy of sources below:

Ben Legler, Richard Old, Rasbak, & others. (2018). King County Weed Identification photos.  https://www.kingcounty.gov/services/environment/animals-and-plants/noxious-weeds/weed-identification.aspx 

Benning, J. (2020). Tree Guide Photos.  http://www.tree-guide.com/ 

Bixby, M. (2020). Integrated Weed Maintenance Fall 2020. Oregon Invasive Species Council.

Lesh, J. (2019). Woody Weeds of Clackamas County. WeedWise Program, Clackamas Soil and Water Conservation District. Oregon City, OR.

State of Oregon Department of Agriculture. (2019). Oregon Noxious Weed Profiles.  https://www.oregon.gov/oda/programs/Weeds/OregonNoxiousWeeds/Pages/AboutOregonWeeds.aspx 

West Linn Parks & Recreation. (2020). Mary S. Young Park. City of West Linn Oregon Official Website.  https://westlinnoregon.gov/parksrec/mary-s-young-park-0