We studied the potential contribution of frugivorous bats to the reestablishment of vegetational diversity in a restored area. We analysed the diets of the bat species and the differences between them in the consumption of fruits of autochtonous and allochthonous species. Planted (autochtonous) species were the basis of diets, especially Solanum mauritianum and Cecropia pachystachya, whereas for allochthonous species we found that Piperaceae to be of particular importance. Carollia perspicillata was the main seed disperser for allochthonous species, and potentially the most important bat in the promotion of vegetation diversity in the study area. Our results suggest that frugivorous bats are especially important in the reestablishment of vegetation in disturbed areas, and that restorarion efforts should focus on the planting of different zoochorous species that would guarantee a high year-round fruit production, thereby facilitating natural plant reestablishment by frugivorous bats in regenerating areas.

Seeds of Cecropia hololeuca were submitted to regimes of constant and alternating temperatures, associated with photoperiods of white light, "shade light" and continuous darkness under controlled conditions in laboratory. Seeds did not germinate at constant temperatures of 10°C to 20°C and above 35°C. Seeds only germinated in the darkness when the temperature was alternated. "Shade light" inhibited germination. We concluded that the regime of alternating temperatures suppressed the light effects on seed germination of this species.

-(Physiological responses of Amazonian flooded plants to the global climate change). According to the last report of IPCC (Intergovernmental Panel of Climatic Change, 2007) an increase in atmospheric CO 2 concentration to ca. 0.072% is predicted to occur until the middle of this century. As a result, a tandem elevation of temperature of ca. +3 °C and a decrease in precipitation are to be expected. It has also been suggested that this scenario may lead to a gradual substitution of the tropical forest for savanna-like vegetation in Eastern parts of the Amazon. Within this perspective, a worth question is how the tree species that make up the Amazonian floodplains will respond to the global climatic change? Although predictions have been quite pessimistic, flooding of part of the Amazon will continue to occur for several years and it is important to understand its synergistic effects within the scenario of climate change. In this work, features related to plant metabolism and hormonal signaling during flooding is revised, and the possible effects that the climatic changes might have on plants from the Amazon are discussed. The information available in the literature suggests that under flooding, plants tend to mobilize storage compounds to supply carbon demand needed for maintenance metabolism under the effect of stress caused by the lack of oxygen. In contrast, under elevated CO 2 concentration, plants tend to increase photosynthesis and biomass. With an increase of about 3 °C these parameters may increase even more. Alternatively, with flooding, there is a general decrease in growth potential and it is possible that while favorable conditions of elevated CO 2 and temperature prevail, the positive effects may be counterbalanced by the negative effects of flooding. Thus, the physiological responses might be imperceptible or promote further growth up to the middle of the 21 st Century for most species that occur in the floodplains. However, if temperature and CO 2 levels surpass the threshold of optimal conditions for most plants, a decrease in physiological activity is to be expected.

ABSTRACT

A embaúba é considerada uma espécie pioneira que ocorre na mata Atlântica, principalmente em borda da mata ou em matas secundárias. O presente trabalho teve como objetivo a análise da influência da temperatura e do modo de ação da luz através de curva de fluência resposta, para a melhor compreensão do comportamento das sementes desta espécie. Através de incubações isotérmicas foi determinada que a temperatura ótima de germinação de sementes de Cecropia glaziovi, situa-se entre 25 e 30ºC e a saturação da indução da germinação com luz branca mediada pelo fitocromo ocorreu com 1W.m-2. Embora as sementes de embaúba necessitem de luz de alta razão de V:VE para a indução do processo, a germinação ocorreu em fluência baixa de luz branca, indicando alta sensibilidade dessas sementes ao ambiente aberto, como borda de matas e pequenas clareiras. Estas características indicam a participação do fitocromo B no controle da germinação de sementes nesta espécie.