in Sri Lanka - Ministry of Environment

is very likely to devastate this ecosystem in the near future. Change of the global climate mayexaggerate this situation but this has not been adequately examined so far.All the above mentioned threats directly or indirectly lead to the extinction of threatened speciesfrom the dry land of the country. More than forty locally threatened plant species are foundfrom the dry land of Sri Lanka. Threats in the dry land habitats pose a greater impact onendemic and rare plant species. For instance, nearly 30% of the endemic plants that grow inthe Sri Lankan dry land are under a the threat of extinction.E. Conservation prioritiesConservation of dry zone terrestrial ecosystems is of prime importance for conserving thespecies in these habitats. Using satellite imagery analyses, Legg and Jewel (1995) statedthat closed forests of the dry land of Sri Lanka covers 524,900 ha . The majority of these areprotected by the Department of Wildlife Conservation and the Forest Department of Sri Lanka.However, the wilderness is still being converted to other land uses from time to time whileunplanned and uncontrolled human activities are playing a significant role in their degradation.Therefore, policies should be formulated and implemented to halt the conversion of wildernessareas to other land use types and to prevent selective logging, shifting cultivation and cattleranching in protected areas. Moreover, the strengthening of relevant institutions is vital for theprotection of these ecosystems.F. Research gaps and research needsSome ecosystems of the country, especially the savanna and grassland ecosystems, arenot adequately investigated. The exact locations and the extent of these ecosystems are notaccurately documented while the ecological data required in preparing management guidelinesof these ecosystems hardly exist. The species composition, the eco-physiological requirementsof constituent species, biotic and abiotic factors that affect species composition, distribution andvegetation successions and disturbance responses in these ecosystems should be examined.Compared to these, the dry forest ecosystems have been studied to a certain extent, but morestudies should be conducted to fill certain gaps in the knowledge. Thus, future research shouldfocus on the eco-physiological requirements of dry forest plant species, pollination biologyand diseases as well as pathogens. Moreover, it is vital to investigate the impacts of climatechange and the potential for carbon sequestration in all these major dry land ecosystems. Also,the restoration of degraded dry land ecosystems and sustainable harvesting mechanisms fornon-timber forest products should also be investigated in depth.G. Conclusions and recommendationsDry forests, savanna and grasslands are the three major natural terrestrial vegetation typesfound in the dry land of Sri Lanka. Biodiversity in these ecosystems are adversely affected byvarious biotic and abiotic influences such as habitat destruction, degradation and fragmentation,biotic invasions, forest die-back, over-extraction of forest products and climate change. Thesefacts highlight the importance of conserving the remaining natural dry land ecosystems of thecountry. Protection of dry zone ecosystems should be strictly followed without converting theremaining natural dry zone ecosystems to other land use types. Human impacts especially,the shifting cultivation, selective logging and grazing by feral cattle should be stopped by173