TITLE:
Carbon Sequestration in Tropical Forest Stands: Its Control by Plant, Soil and Climatic Factors
AUTHORS:
K. A. J. M. Kuruppuarachchi, Gamini Seneviratne, Buddhika D. Madurapperuma
KEYWORDS:
Tropical Forests, Carbon Sequestration, Soil Organic Carbon
JOURNAL NAME:
Open Journal of Forestry,
Vol.6 No.2,
February
4,
2016
ABSTRACT: 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.