ORGANIC CARBON STOCK OF Albizia procera, Lagerstroemia speciosa and Cassia fistula SEEDLINGS UNDER CLIMATE CHANGE SCENARIOS M. R. Ullah* and M. Al-Amin Institute of Forestry and Environmental Sciences, Chittagong University, Bangladesh Abstract The organic carbon in plants is stored in the foliage, stems and root systems and most important the woody tissue in the main stems of trees. Ability of forests, trees and vegetation as terrestrial carbon sinks to absorb CO 2 emission and mitigate climate change has attracted wide attention. The aim of the study was to measure the organic carbon stock of three selected seedlings Albizia procera, Lagerstroemia speciosa and Cassia fistula at initial stage under different temperatures using low, mid and high scenarios prescribed by IPCC (Intergovernmental Panel on Climate Change). The study was conducted through randomized block design (R.B.D.) with three samples were taken from each treatment. The result of the experiment was found as follows: the highest total organic carbon was stocked of Albizia procera in mid temperature scenario (1.14 g/seedling) followed by low and high temperature scenarios (0.79 g/seedling and 0.41 g/seedling respectively), Lagerstroemia speciosa in high temperature scenario (0.29 g/seedling) followed by low and mid temperature scenarios (0.27 g/seedling and 0.15 g/seedling respectively) and also, Cassia fistula stocked highest organic carbon in mid temperature scenario (0.39 g/seedling) followed by low and mid temperature scenarios (0.28 g/seedling and 0.09 g/seedling respectively). Under three climate change scenarios, these three seedlings stocked organic carbon which may help to sustainable forest management and also economic benefit for the country and environmental benefit in the international arena. Keywords: Organic carbon stock, Albizia procera, Lagerstroemia speciosa, Cassia fistula, Climate change scenarios Introduction Forest soils and vegetations store about 40 % of all carbon in the terrestrial biosphere, more than any other ecosystem (Matthews et al., 2000). Forests act as carbon reservoirs by storing large amounts of carbon in trees, under story vegetation, the forest floor and soil (Rotter and Danish, 2002). The quantity of C stored in soils is highly significant; soils contain about three times more C than vegetation and twice as much as that which is present in the atmosphere (Batjes and Sombroek, 1997). Bangladesh is a South Asian country situated between 20 0 34′ and 26 0 38′ north latitude and between 88 0 01′ and 92 0 41′ east longitude with an area of 147,570 square kilometers (sq. km) (BBS, 1999). Land uses of Bangladesh mainly with agriculture (64.2 %) and forest (17.8 %). In Bangladesh, forests are characterized by complex spatial vegetation pattern. Tree establishment and growth generated by environmental gradients and topographic differentiation. Forests are often called lungs of the earth, because forest acts as and indicator of environmental quality and contribute to sustainable development in a *Corresponding author: Tel.: +88 01819821666 E-mail: r_ullah101@yahoo.com