IMPACTS OF CARDAMOM CULTIVATION ON FLORAL DIVERS

Knuckles Forest Range is a unique ecosystem and extending to 160 km2 in Matale andKandy Districts of Central Province. Together with the landscape and the climate it has·resulted a variety of natural vegetation types. Among these, sub montane forests arebighly affected by commercial planting of cardamom by villagers and also by large scalecompanies,This research was conducted in Riverston area of Knuckles Forest Range. Selectivesampling was done in the natural forest and in the areas where the undergrowth isdominated with cardamom. Within the areas, three 20 x 20 m plots were established andfollowing measurements were done; no. of species/area, no. of individuals/area and perspecies, vertical stratification in the two types of areas. DBH was measured in trees withmore than Im height.The results depict 48 plant species in natural forest and 31 species in cardamom plantedareas, with a high number of genera and families in natural forest. 29 species out of 48species were only confined to the natural forest areas. Height and diameter distributionpatterns were different in two conditions. Species diversity (Shannon's diversity index)was significantly different and it was 1.1300 in natural forest areas and 0.5678 incardamom plantation. Density of trees (number of stems per ha) also showed suchpattern and the values were 6433 and 537 respectively. Dominance of species accordingto the Importance Value Index (IVI) in the two conditions was also different. Comparisonof endemicity in two conditions showed 45.83% in natural forest and 29.03% incardamom plantation.The results of the present study also provide evidence as to the detrimental effects ofcardamom planting on the ecology of the sub montane forests of Knuckles Range.

Designing green belts in the coastal zone of Hambantota

Tsunami, which occurred in the Indian Ocean on 26th of December, 2004 caused severe damage toSri Lanka's coastline. Hambantota District, situated in the south of the country was among the worstaffected. 19 GS Divisions in the Districts were affected. As a measure towards protection of thecoastline from future such hazards, establishment of a green belt has been suggested by theGovernment. The location of this belt was proposed to be in the strict conservation zone of the coastwhich was 100m in the western coast and 200m in the eastern coast. The limits were then revised andthe present reservation limits were in accordance with those listed in the Revised Coastal ZoneManagement Plan 1997.The present study was conducted with a view to design a green belt for Hambantota District. It washoped to recommend the most suitable species and their arrangement taking into consideration thenatural landscape features of the coastl ine. Further, the modal ities of the implementation of such abelt also was discussed with the existing organisations in the District including govt., non govt, privateand the communities.The exact study area was limited to the coastline between Kudawella to Kubukkan Oya. Data werecollected in 12 sampling locations. The methods used for data collection were, reconnaissance survey,floral sampling, focal group discussions and community survey. In the floral sampling, a transect of10m x SOm was established from the beach towards the inland at each sampling location and all thespecies were identified. The intention of this was to identify the species which are most resistant tocoastal hazards. Focal group discussions were held with the key players in the green belt establishmentin the District. The main aim of this was to identify their level of support and willingness to participatein the Green Belt.According to the results, the coastline of Hambantota can be divided into natural, rural and urbanareas. Among the natural areas, mangroves and sand dunes were prevalent. Recommendations aregiven in the use of most suitable plants for individual areas in the District ie Rekawa, Yala NationalPark. Mahalewaya, Rathupasgodalla and rural areas. Many govt, and non govt. organisations wereinvolved in tree planting. However, there was no coordinated effort. The neighbouring communitiesexpressed their willingness to participate in this exercise especially in tree planting and maintenance.

IMPACT OF LAND USE CHANGES THE CATCHMENT ON THE QUALITY AND QUANT1TY OF WATER IN THE RAJANGANA RESERVOIR

The condition of the watershed plays an important role in the quality and quantity of thewater of reservoirs. Among the factors, which affect the health of a watershed, areclimate, geology and land use management. Rajangana watershed drains water to theRajangana reservoir, which irrigates about 5520 ha in the dry zone.In the present study, total monthly inflows to the reservoir were calculated through awater balance study and water inflows from the catchments were obtained through asensitivity analysis using past records. Land use changes were studied by using existingland use maps (1: 50,000) using GIS software. Some water quality parameters in thereservoir waters were analysed. These parameters were compared with the ones takenduring the past 10 years from past records of the MASL in order to identify any trendswith the changes of rainfall, temperature, land use etc.The results showed that the annual total water inflow and also the inflow during the dryseason decreased with time. These trends correlated with the increase in built up areas,reduction of forest cover. Further, there was a marked increase of the pH and alkalinity inthe waters with time