It is unknown how rising temperatures could impact cheatgrass, an invasive annual grass that is widespread in western North America and has led to larger and more frequent wildfires. Researchers used a new experimental method to manipulate soil surface temperature at two locations in the western U.S.: Boise, Idaho and Cheyenne, Wyoming. Black or white gravel was spread over experimental plots at each location before cheatgrass seeds were planted. The researchers found that black gravel increased the temperature of the surface soil compared to white gravel, which resulted in earlier cheatgrass germination and faster growth. Black gravel plots had a growing season approximately 3 weeks longer than white gravel plots. These results suggest that a warming climate could lead to a longer cheatgrass growing season, with the potential to further escalate the cheatgrass-fire cycle.  

Maxwell, T.M., Germino, M.J., Romero, S., Porensky, L.M., Blumenthal, D.M., Brown, C.S., and Adler, P.B., 2023, Experimental manipulation of soil-surface albedo alters phenology and growth of Bromus tectorum (cheatgrass): Plant and Soil, Online. https://doi.org/10.1007/s11104-023-05929-4