Warmer and drier climate conditions in western U.S. forests are making it harder for trees to regrow after wildfires, according to a recent study undertaken by dozens of researchers from around the country.

“We can’t expect that forests will recover following wildfires the way they have in the past,” said Kimberley Davis, lead author of the study, published in the Proceedings of the National Academy of Sciences of the United States of America. The research considered the aftereffects of 334 wildfires that occurred between 1984 and 2018, and how well eight species of conifer trees regenerated after those burns.