Clackamas County Warming Centers. Warming Centers in Clackamas County.

Rose Clarke

Thinning and Selective Management in Mature Forests

Hopkins Demonstration Forest

16750 S. Brockway Rd.
Oregon City, OR 97045
United States

Nov 16, 2019 9:00 am - 3:00 pm
Event Cost
Contact name
Jean Bremer
Contact phone

Do you have older trees and forests – 60 to 80 or more years old? Are you interested in periodic thinning, selective harvesting of trees or small patches, and keeping options open for the future?

Attend this field workshop to learn about options for managing older Douglas-fir forests with thinning and selective cutting rather than larger clearings. Led by OSU Extension Forester Glenn Ahrens and Silviculture Specialist, Steve Fitzgerald, the workshop highlight 25-year results of thinning and selective harvesting in three demonstration areas at Hopkins Demonstration Forest. Along with what we are learning at Hopkins, this will be an opportunity to learn from the experience of other participants in the workshop, including landowners, forestry consultants, and loggers.

We will explore both the challenges and benefits of managing older Douglas-fir forests with thinning and selective cutting, including:


  • Protecting soils and trees with repeated machine entries – high level skills and equipment needed to thin large trees
  • Need for well-developed road systems
  • Maintaining quality and market value of large trees – avoiding large branches and knots
  • Minimizing invasive weeds and competition from understory vegetation


  • Enjoying mature forest conditions, large trees, diverse species and layers, wildlife habitat, aesthetics, etc.
  • Periodic income, increasing percent growth rate in thinned stands
  • Potential to produce higher value - large sawlogs, poles, or veneer
  • Maintaining healthy tree crowns and future options

Coffee and morning snacks provided starting at 8:30am. Bring your own lunch, dress for the weather and be prepared for some walking in the forest demonstration areas.

The fee is $15. Space is limited, so pre-registration is required. Register above. 



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