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Resources for Volunteers

Tree ID guides and other resources from the Tree Inventory Project

Volunteer Roles

Volunteers are the backbone of the Tree Inventory Project. So far, over 2,000 individuals have given around 25,000 hours of their evenings and weekends to map trees in neighborhoods across the city. Over the years, this program has offered a variety of ways to get involved:

  • Data Collectors show up at workdays ready to inventory trees! No experience necessary.
  • Team Leaders attend classroom and field training prior to the inventory season in order to learn how to identify and measure the trees they find. At workdays, Team Leaders lead 1-3 Data Collectors in the field.
  • Neighborhood Organizers plan between 1-4 events throughout the summer, recruiting friends and neighbors to join the inventory. 
  • Arborists-on-Call are experts in tree identification and assessment, traveling between groups on bike or on foot, answering questions as they come up.
  • Neighborhood Tree Teams take what we've learned from the Inventory to develop a Tree Plan as well as projects to improve their corner of the urban forest. Learn more about the Neighborhood Tree Teams program.


Volunteers have identified over 300 species of trees across the city! The Tree Inventory Manual and Team Leader Presentation below show you what we measured, the tools we used, and guides for how to identify many of the most common trees in Portland.