Soil seed banks, the reserves of viable seeds on or beneath the soil surface, are a critical component in conserving biodiversity and restoring degraded landscapes. A review by Wakshum Shiferaw of Arba Minch University and Sebsebe Demissew and Tamrat Bekele of Addis Ababa University examined how seed banks vary across land uses, climates and vegetation types, and how their persistence influences conservation and restoration planning.
Seed Bank Characteristics
The review found that seed bank density generally declines with soil depth and seed age. Smaller, elongated seeds with hard seed coats tend to survive longer than larger seeds, which are often less persistent. Herbaceous plants typically dominate soil seed banks, while woody species are less represented and often rely more on seed rain and vegetative regeneration for renewal.
Influence of Land Use and Disturbance
Disturbance and land management practices strongly influence seed bank composition. Moderate disturbance, such as controlled grazing, can increase both seed density and diversity. Intensive tillage, however, reduces seed reserves. In many ecosystems, the species present in the seed bank differ significantly from those in above-ground vegetation. Seed banks often contain a greater diversity of species, serving as a genetic reservoir that can support recovery after disturbance.
Ecological and Restoration Functions
Soil seed banks perform multiple ecological functions. They buffer against environmental change and enable recovery following events such as fire, drought or land conversion. In restoration projects, seed banks can provide a cost-effective source of regeneration. Where seed banks are depleted, supplemental measures such as direct seeding or enrichment planting may be necessary to achieve desired restoration goals.
Implications for Conservation
Understanding seed bank diversity, density and composition can guide conservation strategies, improve restoration outcomes and support land-use planning, particularly in arid and degraded environments. The review emphasizes the need for further research into the relationship between soil seed banks and above-ground vegetation, as well as improved methods for assessing and managing seed banks in different ecosystems.
Source: Shiferaw, W., Demissew, S., and Bekele, T. (2018). Ecology of soil seed banks: Implications for conservation and restoration of natural vegetation: A review. International Journal of Biodiversity and Conservation, 10(10), 380–393. https://doi.org/10.5897/IJBC20...