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Regional Tree Census

Arborist examining leafed out tree up close in sun

The 2020 Chicago Regional Tree Census is a scientific project to count and assess the state of trees across the seven-county Chicago region. The census is being conducted by The Morton Arboretum with support from the Illinois Department of Natural Resources. Knowledge from this important study will guide tree planting and care in Chicago-area communities and inform scientific research about urban trees.

The study will help area residents, homeowners, local governments, planning agencies, scientists, universities, and community groups in this region understand:

  • How many trees the region has
  • What kinds of trees they are
  • How old the trees are
  • What trees do for area residents
  • The health of the region’s trees
  • How the region’s urban and community forest is changing

Combined with the data from a similar study conducted in 2010, the 2020 Chicago Regional Tree Census will provide a clear picture of change in the region’s trees and a baseline for future research and forest growth efforts. For example, the comparative data will show researchers how many ash trees have been lost to the emerald ash borer infestation of recent years. Census results also will show how trees may be vulnerable to other pests. The data will provide important guidance for tree planting and management to make communities greener, healthier, and more beautiful. 

The study will be conducted between June and October 2020. Crews will not count every tree in the region individually. Instead, they will visit 1,600 randomly distributed sample plots. These plots also were surveyed in 2010, so the data from the two studies will be comparable. An analysis of the sample plot data will be used to assess the current state of trees in the entire region, using scientific models developed by urban foresters at the U.S. Forest Service of the United States Department of Agriculture.

The study is being conducted by the Davey Resource Group, Inc., a wholly owned subsidiary of the nationwide Davey Tree Expert Company. Trained interns from the Student Conservation Association will accompany Davey Resource Group staff on the census crews.

The sample plots are on both public and private property. By allowing census crews access to outside areas, property owners and residents will be helping trees, supporting science, and contributing to a greener future for the region.

For more details on how the project is being conducted, see our Frequently Asked Questions.

Learn more about the 2010 Chicago Regional Tree Census.

2020 Tree Census Partners


Support for this important project has been provided by the Illinois Department of Natural Resources, The Morton Arboretum, and private sources.