A population of the grass Danthonia spicata growing in a pine-hardwood forest in northern lower Michigan was studied before, during, and after a period of major disturbance. Samples of the aboveground population were collected after clearcutting but before fire, 9 days after fire, 10 months after fire, and 13 months after fire. Change was examined by growing clonally replicated genets in a series of light and watering treatments in the greenhouse. There was a significant change in the composition of the population after fire. Genets collected following the fire grew faster and larger in the 100% light treatment than individuals collected before the fire. Differences among collections were small or not significant for plants grown in the 20 and 6% light treatments. The watering treatments showed little or no effects. Although there are limitations in the interpretation of common garden studies, the differences among collections appear to have a genetic basis. The growth characteristics of genets collected after the fire shwoed possible adaptation to postfire conditions. These results suggest a greater importance for genetic adaptation in the persistence of D. spicata during secondary succession than had been concluded from earlier experiments.