Terrestrial bromeliads as seed accumulation microsites in a xerophytic forest of Southern Chaco, Argentina

Abstract

The understory of the Schinopsis balansae forests of Southern Chaco isfrequently covered by dense populations of two bromeliad species(Aechmea distichantha and Bromelia serra). These bromeliads usually actas traps capturing propagules and litter falling from the canopy. Somepopulations of these bromeliad species have been removed to ease cattlemanagement, without considering their possible effects on forestregeneration. Therefore, the objective of this work was to evaluate theimportance of both bromeliads as microsites for seed accumulation ofwoody and herbaceous species. Ten plots with bromeliads were selected,where one soil sample and one plant of each species were taken. From thematerial collected among bromeliad leaves, the seeds and propagules wereseparated. Likewise, soil samples were washed and the seeds wereseparated from the litter collected. Seeds were determined tomorphospecies and counted. There were 352 seeds (230 on bromeliads and122 in the soil) from 48 species (10 woody and 38 herbaceous species).Seed abundance of woody species was higher on bromeliad plants (70seeds) than on the soil (six seeds). In contrast, a higher richness ofherbaceous species was recorded on the soil. Therefore, both bromeliadsseem to be important microsites for seed accumulation of woody species.However, it is not known whether bromeliads are a safe site for seedlingestablishment.