As California burns, a recent study may point to a new culprit in feeding the blaze: invasive grasses. Ecologists mapped wildfires across the United States from 2000 to 2015 and compared them to the locations of 12 species of nonnative grasses, including cane grass and buffelgrass, The New York Times reports. For at least eight species—which come from Europe, Africa, and Asia—more grass meant more fires, the researchers report this week in the Proceedings of the National Academy of Sciences. That’s likely because the grasses often take over barren areas or places that used to host less flammable native shrubland. Dry weather can then turn fields into kilometers and kilometers of ready kindling—and after a blaze, many invaders are quick to recolonize burned earth, which could lead to a vicious cycle of recurring fires.