The Morton Arboretum has released the results of its 2020 Chicago region tree census. Findings include the loss of an estimated 6 million ash trees, felled by the emerald ash borer. Chicago's canopy cover decreased from 19% to 16%, largely because of the disappearing ash trees, the census found.The census report's authors expressed a need for Chicago to diversify its tree population. On a positive note, the census did find an increase in the total number of stems, up from 157 million trees in 2010 to 172 million trees in 2020. There are nearly 200 different species represented in that count regionally (103 in Chicago).
