THE FLORISTIC WEALTH AND DIVERSITY OF MYRISTICA SWAMPS, THE FRAGILE FRESH WATER ECOSYSTEM OF WESTERN GHATS.

Kerala, the southernmost state of India, located between 8o 17 30 and 12o 47 41 N. Latitude and 74o 52 47 and 77o 22 12 E. Longitude. The State is boarded with sea shore of Arabian Sea and undulating hills of the Western Ghats. The Western Ghats, biodiversity hotspot of Peninsular India are well known for the existence of diverse ecosystems. The Myristica swamp is one of the rare ecosystems with a restricted distribution confined to valleys of foothills in Kerala, Uttara Karnataka, Goa and Maharashtra states. The swamps are unique for floristic wealth and ecological functioning, being the abode of amphibian richness with adaptive features, to survive in waterlogged condition. A total of 120 Myristica swamps were reported in Kerala which together contains 246 species of angiosperms belongings to 186 genera from 83 families. Among these, 77 species are endemic to India, 10 are endemic to Peninsular India, 67 are endemic to the Western Ghats, 58 are endemic to southern Western Ghats and 34 species shows cosmopolitan distribution. The majority of the endemic species belongs to the family Rubiaceae followed by Araceae, Fabaceae, Lauraceae, Dipterocarpaceae and Euphorbiaceae. The swampy members are also important in conservational status, 49 species belongs to various threat categories of IUCN, out of which, 12 species are endangered 5 species are critically endangered and 8 are vulnarable 19 are under least concern, 3 species are near threatened and 2 species are data deficient. The Floristic diversity varies from 0.710 to 0.790 and species richness and equitability varies from 1.08 to 1.32 and 0.75 to 0.83 respectively. The dominant tree species areMyristica fatua var. magnifica and Gymnacranthera canarica, being the specialist species among which M. fatua is hither to known only from Myristica Swamps, germinate, establish and survive in fresh water swampy conditions, and can be considered as the flagship species. The other Myristicaceae members viz. Myristica malabarica, Knema attenuata are commonly seen as generalist species. The riparian species like Lophopetalum wightianum, Lagerstroemia speciosa, Hydnocarpus pentandra, Holigarna arnottiana, Syzygium travancoricum, Vateria indica etc are the common associate species. It is observed that, all the swamps are under ecological succession due to anthropogenic or natural reasons and vegetation have been exploited which in turn is obviously in the path of extinction due to multiphase development and subsequent fragmentation. The floristic diversity indices and floristic composition and community status of Myristicaceae members also vary with vegetation succession due to changes in the selective recruitment and changes in the functional dynamism. The present investigation highlighting the floristic wealth and diversity of myristica swamps of Kerala with respects to their salient conservational features.