in Sri Lanka - Ministry of Environment

Gunatilleke, 1991). High population density of the lowland wet zone and the developmentactivities associated with the rapid increase of population and extensive dependence onsubsistence agriculture have caused considerable pressure on this biologically rich ecosystemof the country. Human encroachment by communities living in the peripheral areas is anothermajor threat for this ecosystem. Habitat disturbance together with the fragmentation of theforests caused several negative impacts to the ecosystem, for instance restricted dispersal,isolation of populations, genetic erosion etc.Considering the floristic wealth of lowland wet zone of Sri Lanka, in situ conservation of nationallyand globally threatened endemic plant species with special emphasis on their population sizesshould have high priority. A study conducted in nine different sites of lowland wet zone revealedthat 93% of endemic plant species are either endangered, vulnerable, or rare according to theIUCN Red List criteria (Gunatilleke and Gunatilleke, 1991). To provide in situ conservation formany of these threatened endemics, the preservation of representative samples of rain forestsin different regions is strongly recommended (Gunatilleke and Gunatilleke, 1991).In the past, natural forests were largely used for the extraction of timber. Little attention was thenpaid to other useful resources, largely non-timber, that were traditionally being extracted by theperipheral communities around forests. However, these non-timber resources contributed tothe livelihood of the local people, who depended on the forests for their food, medicine and otherdomestic requirements for generations (Anon., 1995; Gunatilleke et al., 1994). Conservation ofnon-timber forest products through an effective buffer zone management system around thelowland wet zone forests would certainly reduce the pressure on the ecosystem.Sri Lanka has a strong tradition in conservation practiced by communities in harmony with, andpartial dependence on, the natural forests. Thus, it provides an excellent setting to examinehow these tropical rain forests can be managed for multiple uses, following a system thatis socially acceptable, ecologically sustainable and economically viable (Gunatilleke et al.,1994). The multiple use management of natural forests, aims to increase the sustainable flowof both timber and non-timber forest products, while maintaining their value for non-productservices such as biodiversity conservation, soil and water conservation, amenity and socioculturalvalues from natural forests for the benefit of the rural people (Gunatilleke et al., 1995).Experience and the scientific and technical expertise in multiple use forest managementsystems are currently lacking in Sri Lanka. Buffer zones can be recognized as one of the mostsuitable and important areas to implement multiple use forest management, while providing avariety of goods and services.Research gaps and research needsConsiderable amount of research has been carried out, especially on lowland wet zone flora,over the last 3-4 decades. These studies have substantially increased our understandingon of the distribution of species, ecology, forest dynamics and silvicultural and managementpractices of this ecosystem. However, following research gaps could be identified;- Systematics and inventory of lower plants in lowland wet zone of Sri Lanka- Phylogenetics and evolutionary studies on plant taxa to elucidate the phylogeneticrelationships, biogegraphic history etc.178