U.S. Joint Fire Science Program


Date of this Version


Document Type



Fire Science Brief, Issue 89, January 2010


US government work


Researchers took advantage of data collected prior to Colorado’s 2002 Hayman Fire to examine the effects of mixedseverity wildfire on understory plant community development during the first five postfire years. Some declines in species richness and cover were observed immediately following fire, but by postfire year five, they met or exceeded prefire levels, even in severely burned areas. Changes in upland community composition, where they were observed, were primarily due to the postfire recruitment of new species (particularly native short-lived forbs), rather than due to a loss of prefire species. While exotic richness and cover generally increased as fire severity and time since fire increased, the presence of exotics remained relatively low at the end of the study, and has not yet interfered with the recovery of the native understory community.