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 American chestnut, whitebark pine, and several species of ash in the eastern United States are just a few of the North American tree species that have been functionally lost or are in jeopardy of being lost due to outbreaks of pathogens and insect...