Department of Forestry and Environmental Science
UNIVERSITY OF SRI JAYEWARDENPURA, SRI LANKA ../
FORESTRY AND ENVIRONMENT SYMPOSIUM
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|FORESTRY SYMPOSIUM 1996|
B M P Singhakumara
University of Sri Jayewardenepura
The Kanneliya forest reserve and Nakiyadeniya proposed reserve in Galle district and Dediyagala forest reserve in Matara district form a continuous block of natural forest (KDN forest complex) covering 11,146 ha in the south-west lowland hills. The KDN forest complex was logged by the Ceylon Plywood Corporation between 1968 and 1988.
The forest reserves have been assessed for soil conservation and hydrology using the method developed under the National Conservation Review (NCR). Floristic data provided by the NCR on KDN forests were based on four transects and therefore a detailed enumeration of KDN was carried out to locate core areas with high endemism and species richness within KDN forest complex.
Eighty-nine plots, each 500 m2, were marked and enumerated in KDN forest complex. Ecological indices and importance Value Index, which is the expression of the dominance of particular species in different habitats, were calculated.
The diversity index (Shannon's) calculated for the species (>10 cm dbh) found in each plot enumerated at Kanneliya, Dediyagala and Nakiyadeniya showed that there is no significant difference in diversity among the three reserves. The diversity index does not account for the habitat diversity.
The total number of species (>10cm dbh) enumerated at Kanneliya was higher (144) than for Dediyagala (107) and Nakiyadeniya (98). The number of endemic species, individuals and their basal area were also highest at Kanneliya.
Assessment of the overall importance of KDN forests in the present survey for soil conservation and hydrology was based on ranking the combined values for erosion hazard and hydrological importance. Kanneliya is the most important forest reserve of KDN forests complex for head waters protection. It also receives the highest priority for conservation with respect to flood hazard, reflecting its large area, higher stream frequency, higher rainfall and high erosion hazard.
Department of Forestry and Environmental Science,