Seed bank in a restoration area with topsoil transposition in the Caatinga

Abstract

Soil transposition is a nucleating technique that promotes successional dynamics with seed bank transfer. The study evaluated the efficiency of soil transposition in the arrival of new species from the soil seed bank of a Caatinga area undergoing recovery. Plots (32 m²) were established with three treatments—I) no soil translocation (ST); II) soil translocation on 15% of the area (T15%); and III) translocation on 30% of the area (T30%)—with eight replicates each. Two years later, soil was collected from each plot. Eight random samples were also collected from the preserved Caatinga area (positive reference)—the source of the translocated soil. The eight samples from each treatment were placed in a greenhouse and irrigated. We performed the analyses every 15 days, for 150 days, counting the emerged seedlings, species and number of individuals. We subjected the richness, density, and diversity index data to statistical comparison tests. We tested the similarity between the areas using ANOSIM. We also calculated phytosociological parameters. The areas T15% (8.25 ± 0.90 species) and T30% (11 ± 0.53 species) showed greater richness, with a statistical difference between ST and T30% (p = 0.0003). T30% also showed higher density (p = 0.009; average of 393.88 ± 46.63 individuals/m2). According to ANOSIM, the areas are not similar to each other (p < 0.05). Herbaceous species showed higher values of importance indexes (IV) in all areas. For the study site, soil translocation, applied to 30% of the area as a conditioning technique for degraded land, proved promising, enriching the seed bank of the area undergoing restoration.