Carbon Sequestration Potential of Tropical Forest Soils
*1Jackson, O. I.; 1Adeyemi, A. A.; 1Odeleye, O. A.; 1Amoo V. O.; 2Amujo, O. S. and 2Abiodun F. O.
1Environmental Modelling and Management Department, Forestry Research Institute of Nigeria, Jericho, Ibadan.
2Sustainable Forest Management Department, Forestry Research Institute of Nigeria, Jericho, Ibadan
*Corresponding author: mail2oyeen@yahoo.com
Accepted on June 3, 2014
Abstract
World’s soils are under increasing pressure to meet the demands for food, water and energy, leading to loss and degradation of land resources. This study therefore aims to access the carbon sequestration capacity of tropical forest soils in order to convince all stakeholders (i.e. land-owners, policy makers and others) the importance of sustainable management of soils and forest resources. To achieve this, soil samples (0-15cm) were randomly collected from stands of tree species from Onigambari Forest Reserve, Ibadan South-Western, Nigeria. These samples were analysed for bulk density, pH, soil organic carbon (SOC), soil organic matter (SOM) and total nitrogen (TN) contents. The mean values for the pH, bulk density (g/cm3), SOM (%), SOC (t/ha C) and TN (%) were 6.44 ± 0.75, 1.51 ± 0.20, 3.12 ± 1.31, 34.92 ± 8.75 and 0.18 ± 0.08 respectively. Bulk density (g/cm3) was shown to be strongly related to SOC (t/ha C) (r =0.873). The amount of organic carbon stored in the soil is governed by SOC concentration (%) and bulk density, therefore management practices that will improve bulk density and SOC concentrations are important. It was observed in this study that forest soils are important sink of carbon, thus if current trends of rapid and unprecedented change in land use to meet demands for food, water and energy continue, there will be rapid loss of soil organic carbon to the atmosphere in years to come. This will not only exacerbate climate change, but also increase the extent of soil degradation as well as diminish a wide range of important ecosystem services. Strategies that therefore encourage carbon sequestration in soils, which include protection of existing forests to preserve current soil carbon stocks, re-afforestation of degraded lands and the use of soil amendments should be adopted to ensure sustainable management of land resources.