In the past 10 years, millions more ash trees have died, and the invasive buckthorn now makes up 36% of the Chicago region’s trees, census shows

Shirley Davis, 72, who is a TreeKeeper in Chicago, stands with a linden tree she cares for in her neighborhood on April 30, 2021. The TreeKeeper program from the conservation group Openlands trains volunteers to care for trees. (Jose M. Osorio / Chicago Tribune)