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Regional Tree Census FAQs

Davey arborists standing in front of branded pickup preparing to conduct the census


What is the 2020 Chicago Regional Tree Census?

The census is a scientific project to count and assess the trees of the seven-county Chicago region. Knowledge from this important study will guide tree planting and care in Chicago-area communities and inform scientific research about urban trees. 

How is the tree census responding to the public health concerns raised by the COVID-19 crisis?

Plans for the timeline and execution of the census have been modified to take into account the latest Executive Orders for COVID-19 issued by the State of Illinois. In accordance with those orders, tree census crews will follow all recommended safety guidelines issued by county and state health departments, the Centers for Disease Control and Prevention, and the World Health Organization. If there are questions please call 630-559-2037 or email treecensus2020@mortonarb.org

Who is involved in this project?

The study is being conducted by The Morton Arboretum with support from the Illinois Department of Natural Resources. The work of counting and measuring trees will be done by crews from the Davey Resource Group, a wholly owned subsidiary of the nationwide Davey Tree Expert Company, along with trained interns from the Student Conservation Association. The Chicago Region Trees Initiative (CRTI),  a regional collaboration of 200 organizations, will be using the 2020 results to guide future work to achieve a larger, healthier, and more diverse tree canopy for all people living in the Chicago region. 

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

Are you counting every tree in the area?

No. It is not possible to count each tree in the seven-county Chicago region. Instead, the census crews are counting trees at 1,600 sample plots. By analyzing the combined data from these plots, the team will be able to extrapolate the state of trees in the entire region.

Is this project part of the 2020 U.S. Census?

No. The United States Census counts people; this project is only interested in trees. Tree census crews will not be asking questions of property owners or anyone else. This study is being conducted by The Morton Arboretum, a nonprofit scientific institution, and not by the government.   

How does this project involve me?

Census crews will be counting and measuring trees at 1,600 randomly located sample plots. If a sample plot includes a part of your property or residence, we are simply requesting that you permit crew members from the Davey Resource Group to access the outside areas of your property, look at your trees, take measurements of the trees, and make note of other plants growing nearby. They will not damage or impact the trees in any way. By allowing access, you will be helping trees, supporting science, and contributing to a greener future for the region.

Where are the sample plots?

Sample plots are randomly distributed across the seven-county Chicago region, on both public and private property, in a wide variety of places, including residential, commercial, rural, and natural areas. Each sample plot is a circle approximately 75 feet in diameter. Since the circle may overlap streets or property lines, multiple residences may be asked to allow census crews access so they can survey a single plot.

Was a similar census ever conducted prior to 2020?

Yes. A tree census of the Chicago region was first conducted in 2010. If you occupied your property then, you may remember seeing a crew working on that study. Returning to the same plots for this new study allows the project team to see the change in trees over 10 years. You can learn more about results from the 2010 tree census here. [link to our 2010 results page] In 2020, a small number of new plots were added to the City of Chicago and Cook County census areas.  

What do I need to do?

If you are willing to help with this project by allowing access to the outdoor areas of your property, you do not need to take any action. However, if you are not willing or have questions you want answered before you commit, please leave a message at 630-559-2037 or email treecensus2020@mortonarb.org. A tree census specialist will follow up within 24 hours to respond to your concerns and provide you with an opportunity to ask further questions.

When will my trees be measured?

The study will be conducted between June and October 2020. If your property is included in the study, you will receive a notification postcard between the end of May and mid-June, followed by a second reminder postcard a few weeks before the crews begin work in your area. Crews will proceed county by county through the region. 

Who will be on my property?

Census crews from the Davey Resource Group will typically consist of two people. Each crew will include a trained professional technician from Davey and a college student intern from the Student Conservation Association who is learning about the tree care profession. The students will always work under the supervision of Davey professionals. All crew members will be recognizable by their yellow vests and hard hats and will carry official Davey Resource Group identification. Crews will follow all recommended safety guidelines issued by county and state health departments, the Centers for Disease Control and Prevention, and the World Health Organization.

Will you notify me before you access the outdoor areas of my residence? 

Before crews access any property, the procedure will be to alert residents or workers of their presence before proceeding to the survey area. If there are questions please call 630-559-2037 or email treecensus2020@mortonarb.org

What kind of information will you collect?

The crews will note the location, species, size, and condition of all the trees in the sample plot, as well as information about other plants growing nearby. Crews will also have records from the 2010 tree census and will compare those data to the current condition of the trees in the plot. Crews will not record any information about the home, business, or occupants of the property being surveyed.

How will you collect the information?

The crews will use specialized tools (such as clinometers) to safely measure tree height and diameter and to identify each tree’s species and condition. No trees will be damaged or impacted.

Where in the outdoor areas of my property will you be working?

Since the sample plots have been randomly located, the survey area may include the front yard or backyard and may overlap more than one property. For the protection and safety of your property and pets, census crews will close and secure gates.

How long will you be at my property?

The time required for the survey depends on the number of trees and other plants on the plot. In most cases, it should take an hour to an hour and a half to survey each plot.

How will I know when the census crew has been at my property?

The crew will leave notification on your front door when the work is completed.

What will you do with the information once you collect it?

Researchers will combine the data from all the plots for analysis. To protect your privacy, we will never share the exact location where any of the information was collected or provide any information that can identify you or your property in any way.  We are grateful for the willingness of property owners and residents to help with this important study.

What will you do with the combined results?

The data will be analyzed using a software tool called i-Tree, a tool that can help strengthen forest management and advocacy efforts by quantifying forest structure and the environmental benefits that trees provide. Results from 2020 also will be compared to data from the 2010 tree census.

Once analyzed, the data will be used by the Chicago Region Trees Initiative [link to CRTI web page], scientists at The Morton Arboretum, and other researchers, as well as by local government officials and planners to understand the region’s tree population and the benefits trees provide, to develop new policies, and to plan for tree planting and improvements in tree care. 

Governments will use the information to drive policy, such as developing tree ordinances or deciding how to fund tree care. Scientists will look for patterns and changes in these data to help decide what questions are important to research.

What will you learn from this study?

From the data collected about the Chicago region’s trees this year, the project team will be able to report:

  • How many trees the region has
  • What kinds of trees they are
  • How old the trees are
  • The general health of the region’s trees
  • The impacts of trees on the region’s ecosystem, such as on air pollution removal, energy savings, and carbon storage
  • How many trees are needed to adapt to climate change and other challenges
  • How the region’s urban and community forest of trees is changing

Will the results of the 2020 Chicago Regional Tree Census be made public?

Yes. After the data are analyzed, the results will be made public in the first half of 2021 and will be available on mortonarb.org

Will this study continue?

The 2020 Chicago Regional Tree Census is part of an ongoing study by The Morton Arboretum of the area’s trees. A new tree census will be conducted every 10 years through 2050. The Chicago region already has more data about its trees than any other metropolitan region in the country. Updating these data every 10 years to reveal how the region’s tree population has changed will make this data set even more powerful for planning, policy, and science.

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.