Poster: Ecophysiology
Abs #
47: Deciduousness and leaf traits in 39 cerrado woody species
Cerrado is a biome with a core area in center of Brazil, showing a size equivalent to western Europe, seasonal climate (winter drought and wet summer), and around 1700 woody species growing in different physiognomies. Deciduousness, photosynthetic capacity on area (Amaxa) and on mass (Amaxm) bases, leaf N and P contents and their use efficiency were determined in 39 cerrado woody species growing under natural conditions. Four phenological groups were found (deciduous, semideciduous, brevideciduous and evergreen) and the mean values of mentioned leaf traits were compared among them. Surprisingly, there were not significant differences (P<0.05) among the phenological groups concern all leaf traits evaluated. Taking in account the trade off between leaf features and leaf longevity, cerrado woody species could show the same leaf life span. Considering that the cerrado deciduous species has the leaf life span around one year, the other cerrado phenological groups should show equivalent leaf longevity. It was possible to compare the values of Amaxm, SLM, and leaf N on mass bases among studied species with leaf life span equal or greater than 12 (evergreen) or 6 (deciduous) months from other biomes. In this last comparison the cerrado woody species stayed between deciduous and evergreen species, confirming the leaf life span around one year irrespective the deciduousness in cerrado. Thus, If there is a trade off between leaf characteristics and leaf longevity there is not an equivalent compromise between leaf life span and deciduousness. Hence, the foliage maintenance in studied species could represent a particular strategy of resources acquisition but leaf longevity is just a feature imposed by ambient conditions.
