Harnessing the carbon sequestration potentials of forest soils: strategies for climate change mitigation and adaptation

Climate change is the hottest ecological issue in the world today. It is brought about by the increased concentration of greenhouse gases (GHGs) in the atmosphere which act as shield that traps long wave radiation from the earth thus causing global warming that triggers climate change. Forest soils contain about one half to two-thirds of the 1240 Pg carbon stock in the forest ecosystem. Soil organic carbon (SOC) is of significance to climate change because among the forest ecosystem C stocks it has the longest residence temp. Hence, harnessing the carbon sequestration potentials of forest soils is important in the mitigation and adaptation to climate change. The amount of SOC depends on natural factors such as climate, topography and natural forest disturbances as well as anthropogenic activities that affect the forest ecosystem such as land use and land use changes. Management options to chance the potentials of SOC in mitigating climate change may be grouped into three approaches: conservation management of existing C stocks, storage management to expand C stocks and substitution management of forest biomass for fossil fuels. Conservation of existing SOC stocks may be done by controlling deforestation, reduced impact logging, protection of existing forest stands, reduced cultivation, and fire and pest and disease control. Storage management for expansion of soil C stocks includes forestation or tree plantation establishment, choice of species, use of soil ameliorants like fertilizers and bioinoculation and agroforestry. Substitution management, the practice of transfer of biomass carbon to products that lessen the use of fossil fuels as in biofuel plantation strategies for SOC consist of adjustments in natural systems in response to climatic stimuli to moderate harm due to climate change. Suggested adaptation strategies include soil and water conservation, bioinoculation, residue management, fertilization,and tree improvement to develop drought and pest and disease-resistant varieties of forest trees. The influence of topography, land use, species, bioinoculation and fertilization on SOC were presented. SOC was generally higher in upper elevation forests. Primary data show that SOC is built up after years of logging in protected areas and that forest species differ in their SOC sequestration potential. SOC is increased with bioinoculation in degraded lands and is favored under legume species whether in tree plantation or agroforestry systems. The effectiveness of mitigation and adaptation strategies in enhancing carbon sequestration in soils may be assessed using direct on-site methods for ground truthing, indirect remote sensing techniques and use of default values. It is necessary to conduct further studies on soil carbon sequestration to enable generation of more baseline data to help in policy formulation. Capacity building and mainstreaming of principles of climate change into national education programs will increase public awareness and participation in the implementation of strategies on mitigation of and adaptation of climate change.