Soil Seed Banks and Regeneration of Neotropical Dry Deciduous and Gallery Forests in Nicaragua

Today, the depletion of tropical dry forests and the need for their restoration are well recognized. In restoring degraded forests, the first step is to quantify the actual and potential levels of natural regeneration, examining the role of soil seed banks as propagule donors. In this study, we assessed the composition, density and spatial distribution of the soil seed bank and seedling populations in dry deciduous and gallery forests of the Chacocente Wildlife Refuge in Nicaragua. A total of 17 species were found in the soil seed bank of the deciduous forest, with a viable seed density of 466 seeds/m(2). In the gallery forest, a total of 24 species were found in the soil seed bank with a viable seed density of 1257 seeds/m(2). The spatial analysis of the soil seed bank revealed clumped and uniform distributions in both forests, depending on the species. The total seedling density in the deciduous and gallery forests was 62 50 and 6600 individuals/ha, respectively. The spatial distribution of seedling populations varied from clumped to uniform depending on the species. The similarity between the soil seed bank, seedling layer and above-ground vegetation was low in both forest sites. It may be concluded that the number of seed bank species and the quantity of soil-stored seeds are relatively low. Regeneration was abundant in some species, but poor in many others. The natural regeneration process should therefore be assisted through direct seeding, planting seedlings and manipulation of the site to improve environmental conditions for seedling establishment and growth.