Internal water storage in savanna trees.

SCHOLZ F.G., BUCCI S.J., GOLDSTEIN G., MEINZER F.C.

Montreal

Simposio; IX International Congress of Ecology.; 2005

Neotropical savannas are characterized by marked seasonality of rainfall. Features related to water use and water balance are keys factors of tree adaptation to the environment. We studied relative capacity of water storage and its functional significance in plant-water relations of savanna woody plants. Relative water storage capacity was determined by the moisture release characteristics and components of hydraulic architecture. Trunks diameter changes were measured separately on the xylem and on the whole stem in order to distinguish the contributions of the xylem and others tissues Daily fluctuations in trunk diameter were consistent with the shrinkage and swelling in tissue due to capacity exchange of water between internal storage compartments and the transpiration stream. Water storage in savanna plants tissue is an important homeostatic mechanism that constraints leaf water potential at adequate values to gas exchange.