The Biology of Viola Fimbriatula in a Natural Disturbance

Individual plants of Viola fimbriatula which germinated from buried seed in two tree blowdowns in 1975 were censused for 6 yr. Growth, seed production, and mortality were monitored at fortnightly intervals. Only seedlings of the cohort established immediately following the disturbance grew large enough to produce seed. The performance of individuals within this cohort was highly skewed, and both reproduction and survival were correlated with individual size. After 1977 the conditions in the blowdowns which initially stimulated germination, growth, and reproduction rapidly deteriorated for V. fimbriatula, and the populations declined to extinction. We conclude that individuals of V. fimbriatula, interacting with the habitat conditions of this natural disturbance, display many of the traits characteristic of species commonly associated with disturbance. In this habitat the dynamics of the entire population are determined by the relative performance of individuals immediately following the disturbance.