Geographic patterns of the fruit traits from Atlantic forest: environmental and ecological relationships of the dispersal modes / Padrões geográficos das síndromes de dispersão e características dos frutos de espécies arbustivo-arbóreas em comunidades vegetais da Mata Atlântica

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

Fruits with seeds dispersed by vertebrates are very frequent in tropical forests. However, there is a great variation in the proportion of zoochoric fruits when different communities are compared. Atlantic forest might have between its species, similar proportion of biotic dispersal modes comparing with other tropical forest communities but, its communities might show differences between if vegetational differences are considered. In the first chapter of this dissertation, the seed dispersal syndromes of shrub and tree species had been quantified for the domain of Atlantic forests and its communities had been compared between the three types of forest vegetations types that compose it. The forests humid forest, the stational semidecidual and the stacional decidual forest had been also compared in relation to others zoochoric fruit variables related as the type of disperser (birds, mammals or mixed), size of diaspore (diameter and length) and color of the fruit. Information has been taken for more than 2000 species of plants, compiled for 188 communities in the domain of Atlantic forest. The forests differs from each other. The communities of the humid forest have higher proportions of zoochory, higher proportion of bird dispersed fruits, smaller diameter means and higher mean of preferential colors related to bird dispersion. In the second chapter, considering that vertebrate dispersed species increase from temperate forests to the most humid forests and varies according to other environmental factors as altitude, dryness, soil type, oxygen availability, nutrients, light, and availability of dispersers, we verified which climatic and special variable influence the dispersal modes and the fruit traits in communities at the domain of Atlantic forest. The analyses had involved Spearman rank correlations and regression linear models between explanatory variables (temperature, precipitation, distance from the ocean, latitude, longitude, and others). The main results found are: (a) vegetal communities with higher proportion of zoochory have more bird dispersed fruits between its species than mammals fruits, and have also smaller fruits; (b) the altitude is a gradient where higher vegetal communities with lower temperatures show higher proportions of ornitochoric species, with smaller diameter diapores.

ASSUNTO(S)

forest dispersal syndromes florestas fruit dispersão de sementes fruto forest ecology ecologia florestal comunidades vegetais vegetal communities

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