Soil seed bank in pantanal riparian forest: Persistence, abundance, functional diversity and composition

Abstract

The soil seed bank is a regeneration strategy for most plant species in wetlands such as the Pantanal. Soil depth is an indicator of seed bank persistence. Therefore, our objective was to assess the species composition potentially persistent in the soil seed bank, and verify the effect of depth on seed bank abundance, diversity and functional composition. We collected 40 samples (10 x 10 x 5 cm) at four depths: 0-5, 5-10, 10-15 and 15-20 cm, in ten areas along the Paraguay River (N = 10/depth). We placed the samples in trays in the greenhouse, and recorded the seedlings emergence for three months. We found 44 species from 16 families. Most species are perennial, autochoric and hydrochoric, graminoid and herbaceous, with vegetative propagation via basal regrowth. The abundance, species and functional richness decreased with increased depth. We did not find differences in species and functional composition between depths. The species share traits both related to regeneration and persistence niches in different soil layers, which indicates similarity in the functions executed by the community over a 0-20 cm depth soil profile. Species with potentially persistent seed bank also have several functional traits that allow the long-term persistence of individuals in the community, such as vegetative propagation, which confers a high potential for plant community resilience.