The timing of reproduction by organisms inhabiting seasonal environments is characterized by a sequence of phenological events. These events may be determined by various factors including density-dependent resource limitation, size and abiotic factors. As a result, individuals would be expected to adjust their reproductive cycle according to variation in the environmental conditions from year to year. Understory plants have limited bright period from snowmelt to canopy closure time, which vary from year to year. Because, initiating reproduction in many understory plants depends mostly on resources stored in the previous season, the probability of flowering or not may depend on the length of bright period. The objective of this study however is to clarify the life-history strategy of forest floor plants under different growing season length.