Author(s)

K. A. J. M. Kuruppuarachchi¹, Gamini Seneviratne², Buddhika D. Madurapperuma^3*

¹Department of Botany, The Open University of Sri Lanka, Nawala, Sri Lanka.
²Microbial Biotechnology Unit, Institute of Fundamental Studies, Sri Lanka.
³Department of Environmental Science and Management, Humboldt State University, Arcata, CA, USA.

This study investigated the relationships amongst floristic, soil and climatic parameters and their control on carbon sequestration (CS) in two selected forest stands of Sri Lanka. Representative sampling sites were selected from the dry zone (Sigiriya forest sanctuary) and the wet zone (Udawattakele forest reserve) of Sri Lanka. Litter and soil samples were collected from each sampling site randomly in monthly intervals to cover an annual cycle. Plant biomass carbon stocks were calculated using standard biomass equations. Soil carbon stocks were determined by chemical oxidation and loss on ignition (LOI) methods. Principle Factor Analysis and multiple regression were used to quantify the relationships among the plants, soil and climatic variables. Plant biomass carbon stocks of the forests were governed by labile and stable C fractions, soil moisture, and plant diversity. The soil fulvic fraction acts as a focal point of interacting the variables such as soil N, free litter fraction (FLF) and humic fraction. During dry period in the dry zone forest, CS was governed by maximum relative humidity through an atmosphere-floor litter-soil continuum. Air temperature and FLF play a vital role in determining soil N. In addition, MacIntosh distance (U) diversity index showed a significant positive relationship with soil N. The dry zone forests are seen to be more climatic sensitive and vulnerable than the wet zone forests in Sri Lanka due to influence of more climatic parameters that govern the soil organic carbon fractions.

Tropical Forests, Carbon Sequestration, Soil Organic Carbon

Kuruppuarachchi, K. , Seneviratne, G. and Madurapperuma, B. (2016) Carbon Sequestration in Tropical Forest Stands: Its Control by Plant, Soil and Climatic Factors. Open Journal of Forestry, 6, 59-71. doi: 10.4236/ojf.2016.62006.