Temporal and spatial variations of propagule deposition in the riparian zones of mountain rivers

Abstract

AbstractAlthough dispersal is important for riparian plants, few studies have evaluated the variations of species richness and composition of propagules deposited by different dispersal mechanisms. In the present study, we evaluate the temporal and spatial variations in the diversity of propagules deposited by hydrochory and by other types of dispersal along mountain rivers. We sampled the propagules deposited in the riparian zone on a distance gradient with respect to the site of origin of the rivers in two seasons. We found no differences in the number of propagules between seasons. In the rainy season, we observed a greater number of species deposited by hydrochory, while for other types of dispersal there was a greater number of species in the dry season. Differences in composition were observed for hydrochory but not for other types of dispersal. There were no changes in the number of propagules deposited along the river by hydrochory, while for other types of dispersal an increase was observed in the dry season. A lower number of species deposited by hydrochory along the river was observed during the rainy season. Finally, we observed that turnover increases for other types of dispersal in the dry season but not for hydrochory. The results underline the importance of types of dispersal other than hydrochory in the contribution of propagules dispersed and the temporal and spatial particularities of the hydrochory in mountain rivers.