Morfofisiologia e comportamento fenológico de plantas em dois níveis altitudinais na savana neotropical

Abstract

Neotropical savannas are seasonal ecosystems that occur in the Americas and are denominated Cerrado in Brazil. It presents phytophysiognomies distinguished by the size of the individuals, especially the Rupestrian fields that occur in areas of high altitude (> 900 meters). For this study, two areas were chosen as models: the campo sujo at 1.400 meters of altitude on the top of the Rupestrian field (CSRF), and the typical and continuous campo sujo (TCS) at the base of the Rupestrian field, at 700 meters of altitude. These areas were selected to evaluate the plant responses related to three parameters: altitude, leaf phenology and seasonality. The phenology, plant anatomy and physiology data were obtained using Byrsonima verbascifolia, Roupala montana and Solanum lycocarpum. These taxa were selected based on the occurrence in the model areas, the satisfactory sample size and to fit into two leaf phenology: evergreen (R. montana and S. lycocarpum) and brevideciduous (B. verbascifolia). The abiotic data found for the dry campo sujo on Rupestrian fields show a less stressful habitat than what was expected, with leaf morphophysiological plasticity in response to abiotic factors, such as humidity, temperature and wind. A few physiological differences were found between areas, which may reflect the high anatomical modifications. The species of the same leaf phenology did not present the same physiological behavior in dry and wet seasons, being contrary to the initial hypothesis.