Variability in the germination of spores among and within natural populations of the endangered tree fern Dicksonia sellowiana Hook. (Xaxim)

The objective of this study was to analyze the existing variability in the germination of individuals' spores collected from two natural populations of Dicksonia sellowiana in southern Brazil. The largest intrapopulational variation was observed for the spores germination. These results suggested the existence of adaptative strategies that favored the gradual and continuous entrance of new individuals into the gametophytic population. The behavior of the individuals of the species within each population followed a similar pattern of initial development, in spite of conspicuous differences in the population structure. This showed a low differentiation between the populations and the existence of adaptative strategies which were common to both communities