Phylogeny, fruit traits, and ecological correlates of fruiting phenology in a Neotropical dry forest.

Abstract

In tropical dry forests, a high interspecific variation in the strategies of fruiting phenology has been documented. Therefore, phenological responses may be mediated by influence of environmental variables, functional plant attributes or phylogenetic inertia. During 2years, we recorded the fruiting phenology of 151 species belonging to 5 different growth forms of a Neotropical dry forest in Mexico. We evaluated the relationships between fruiting phenology, abiotic factors (precipitation, temperature, day-length) and functional attributes (growth form, dispersal syndrome, size and time for fruit development) using phylogenetic least squares models (PGLS). More species had ripe fruits during the dry season (92%) than during rainy months and dispersed their seeds by autochory and endozoochory. We found that fruit development time was positively correlated with fruit size and together the morphological fruit traits (size and dispersal syndrome) showed an important relationship with the growth form, but with a strong phylogenetic signal. Environmental seasonality had a strong influence on fruit ripening time, without a relevant association to the phylogeny of plant species. However, the phenological response to the environment (rainfall and day-length) at the community level was mediated by growth form. In woody species, we documented a high interspecific fruiting variation linked with the different dispersal syndromes. In herbaceous species, fruiting phenology is a trait restricted by the duration of their life cycle byrainfall seasonality, whichin turn might have selected some traits (e.g., dry fruit, presence of spines, explosive dehiscence) for maximizing seed dispersal during the dry season.