In this paper we showed that water deficit affects the wood vessels of Croton floribundus in five areas with different vegetation types: Rain Forest, Semi-deciduous Forest and Woody Savanna. We concluded that variations in the vessels are due especially to water deficit and the number of months with water deficit. Larger diameter vessels occurred in areas with higher water deficit, which may represent a strategy to optimize the water transport in favorable periods. Vessels with smaller diameters occur in areas with lower deficit, which may be related to lower minimum temperatures and frost occurrence, which like drought can cause vessel embolism. In Caetetus Ecological Station, a Semi-deciduous Forest (area of highest water deficit), we observed investments in efficiency and safety, with the occurrence of larger diameter vessels associated with one of the lowest vulnerability indexes and highest proportions of multiple vessels of four or more elements.
Ecological anatomy; mesomorphy; vulnerability; water availability
