Soil Seed Banks in a Forest Under Restoration and in a Reference Ecosystem in Southeastern Brazil

Abstract

The current study aims to characterize the soil seed banks in a forest under restoration and in a seasonal semideciduous forest remnant, as well as to quantitatively and qualitatively compare them in order to evaluate the seed bank potential to influence the restoration process. In total, 60 samples of soil seed banks were collected in two adjacent forests (30 in a 2.18-ha forest undergoing restoration process based on the planting of seedlings belonging to different tree species, after the forest was subjected to bauxite mining activity; and 30 in a 5.30-ha preserved forest fragment). The soil seed bank of the forest undergoing restoration recorded higher density of emerged seedlings than that of the reference ecosystem. Although the shrub-tree species in the investigated forests lacked floristic similarity, the highly similar dispersal syndrome distribution and the successional category of shrub-tree species in them have indicated that both forests underwent ecological processes. Therefore, the restoration process implemented in the mined area has successfully recovered the soil seed bank after a few years.

Soil Seed Banks in Two Environments of Forest Restoration Post Bauxite Mining: Native Tree Plantation and Natural Regeneration

“…The highest proportion of pioneer species and individuals, in both areas under restoration (F1 and F2), confirms data from other studies on soil seed banks in Minas Gerais [33,35,37,43] and in other forest formations in Brazil [44] . Thus, the predominance of native pioneer species in the seed bank is due to the ability to form a persistent bank in the soil due to long seed viability, high seed production, efficient dispersion mechanisms and because they normally show fast growth at full sun, being an excellent indicator of resilience to natural or man-made disturbances [32] .…”

“…These variations in the density of soil seeds in different areas can be related to several factors such as the type of disturbance, history of the area, the presence and quantity of dispersers and geographical barriers [34] . As observed, most of the species and individuals sampled in the seed bank are herbaceous (F1 and F2), which is common in this type of study, as noted by Balestrin et al [20] , Costalonga [35] , Martins [36] and Silva et al [37] as a characteristic of disturbed environments. In addition, the predominance of this life form can be explained by the life cycle of these species, high seed production and history of agricultural use in the area (pasture and coffee plantation), among other factors.…”

“…In F1, the Phyllanthaceae family, with only one species (Phyllanthus tenellus), presented the highest relative density (24.17%) due to the fact that it was the species with the largest number of individuals in the seed bank, followed by the Asteraceae family (21.27%), as also verified by Miranda Neto et al [33] and Oliveira et al [41] . In F2, the Asteraceae (24.93%) and Solanaceae (20.78%) families had the highest relative densities, as well as in surveys carried out in tropical forests in the Atlantic Forest domain [34,37,40] .…”

“…This can be explained by the predominance of species of herbaceous life forms and anemochory dispersion syndrome, which have a survival strategy based on a rapid life cycle and abundant seed production, which are easily dispersed by the wind [11] . Due to this behavior, this family is already consolidated as the most important in several seed bank studies [34,37] .…”

Differences in the soil seed bank of a mining area and its surroundings: a case study inserted in the Cerrado domain

“…Seed banks can contain high diversity of species (Ferreira et al 2015, Braga et al 2016, Silva et al 2019, providing resilience and regeneration of native species (e.g. Guimarães et al 2012, using topsoil) and presenting high density of viable seeds (Martins 2007, Pilon et al 2018).…”