In a first large-scale analysis, ecologists report that invasive grasses can double the number of fires. One species, cheatgrass, has a well-earned reputation as a firestarter, making wildfires worse and more common. It is now clear that this involves more than a single species. The new analysis finds at least seven other non-native grasses can increase wildfire risk around the country, some doubling or even tripling the likelihood of fires in grass-invaded areas.
