Researchers discovered that a new fungal-plant relationship developed between cheatgrass plants (Bromus tectorum) and a fire-dependent fungus (Morchella). The fungus grows into the plant tissues and increases the biomass and seed production of the grass. More biomass leads to more frequent fires and more seed production means more regeneration after a fire. The fungus also increased the ability of seeds to survive heat from fires. The fungal species (phylotypes) originated in western North America and do not occur in Europe. This may be another explanation as to why cheatgrass invasion has been so successful in North America.
Melissa Baynes, George Newcombe, Linley Dixon, Lisa Castlebury, Kerry O’Donnell. 2012.