Reproductive efficiency of the angiosperms of a seasonally flooded forest in the lake Maracaibo basin (Venezuela)

Abstract

Fruit/flower ratio, seed/ovule ratio and relative fecundity were evaluated on 25 species of a seasonally flooded forest in the lake Maracaibo basin and correlated with number and cost of reproductive structures. These estimators, together with the biomass assigned to fruits and seeds and the pericarp/seed ratio, were analyzed between life forms, reproductive systems and seed dispersal syndromes. In general, fruit/flower ratio and relative fecundity were low, but seed/ovule ratio was high. Fruit/flower ratio was negatively associated to the number of flowers per inflorescence, and like the relative fecundity, to fruit and seed weight. Seed/ovule ratio was negatively associated to the number of ovules per flower and to fruit weight. Fruit/flower ratio and relative fecundity were higher in herbaceous, autogamous and/or abiotically dispersed species than in woody, xenogamous and/or zoochorus species which showed higher seed weight, and regarding xenogamous species also higher pericarp/seed ratio than the autogamous ones. Seed/ovule ratio was higher in abiotically dispersed species than in the zoochorus ones. These results suggest a strong influence of number and cost of reproductive structures in species reproductive efficiency.