Figueira, J.E.C., Santos, F.A.M., Miranda, C.A.K., Garcia, Q.S. & Arruda, L.J. 2002. Effects of change in the fire regime at the Parque Nacional da Serra do Cipó on the populations of Paepalanthus polyanthus (Eriocaulaceae). 45th Symposium of the International Association for Vegetation Science, p. 39. Abstract: The rupestrian grassland of the Parque Nacional da Serra do Cipó, SE Brazil, have been frequently burned by man-made fires. These fires induce mass flowerings in the populations of Paepalanthus polyanthus, a monocarpic, long-lived (~30 years), herbaceous plant. The aim of this study is to show how the changes in the fire regime inside the Park are affecting the populations of P. polyanthus. We analyzed the records of fire (date and burned area), made by the Park keepers in the last 13 years (1988-2001). During field trips we obtained the localization of several populations of P. polyanthus, using a GPS, and recorded the occurrence of recent mass flowerings. The relationship between the age and the size of the tallest individuals of P. polyanthus was used to estimate the minimal time each population had developed without being burned. Populations of P. polyanthus are very spread and patchy distributed in the Park. As a consequence of the rise in the burned areas verified in the last years, a large number of populations were burned. The losses of reproductive individuals break the structure of these populations, and the re-incidence of fires delay their restructuring. The size of the tallest individuals found in isolated places, suggest that natural fires are uncommon inside the Park, and the time lag between those fires would have the order of tens of years. |