India, being one of the tropical countries in the world harbours about 690,899 sq. km forest cover, which constitutes 21.02% of the total geographical cover. The current rate of loss of forest cover is estimated at near 2% annually (100,000 sq. km destroyed, another 100,000 sq. km degraded). The average rate of loss or extinction over the past 200 million years is 1 or 2 species per year, and 3 or 4 families per million years. The loss of forest cover/biota is mainly due to various anthropogenic activities. It is estimated that the tropical forests will be reduced to 10 - 25% of their original extent by late 21st century (http://conservationbiology404.blogspot.in/). Therefore, it is essential to conserve the existing biodiversity for the welfare of the present and future generations. The Convention on Biological Diversity made mandatory for the signatories to conserve the areas with rich biological diversity. Mahe, Union Territory of Puducherry, occupies a unique geographical location near to the Arabian Sea. It is situated on the West Coast of the Indian Peninsula between 11? 42? - 11? 43? N and 75? 31? - 75? 33? E, between Kozhikode and Kannur districts of Kerala State. This former small French town, covering an area of 9 sq. km, is 650 km away from its administrative Head Quarters, Puducherry. It also forms a part of the Western Ghats, one of the hottest hotspots in the world. The area enjoys tropical humid climate with summer from March to May and mild winter from December to February. The region receives Southwest Monsoon (June to September), Northeast Monsoon (October to December), winter rain (January to February) and summer rain during March to May. Mahe is rich in biodiversity as it forms a part of the Western Ghats. The climatic condition influenced by the Western Ghats is an advantage to support a rich biodiversity. A comprehensive documentation of floristic diversity of Kerala has been published1 . Floristic diversity of neighbouring two districts of Kerala namely Kannur and Kozhikode that border this region has been studied2,3. Similarly the floristic diversity of Puducherry region has been studied in recent years by many workers4,5,6. A similar work is lacking for this region. Hence, the present study has been undertaken to generate a primary database of the region.
Field survey has been conducted in various regions of Mahe in different seasons. The collected specimens were identified and mounted following standard herbarium techniques7 . The voucher specimens are deposited at MGGA College, Mahe for reference.
The author?s declares none.
The floristic survey revealed the occurrence of 639 species belonging to 450 genera and 127 families (Table 1). Of the total species, 478 are dicotyledons and 162 are monocotyledons. Majority of the species are herbs (326) followed by trees (146), shrubs (104) and climbers (63). The diversity of life forms is depicted in Figure 1. The area is dominated by ten angiosperm families (Table 2). The area also supports 23 species which are endemic to the Western Ghats (Table 3). Further analysis revealed that about 33 species are edible belonging to 29 genera and 24 families8 , about 60 species are medicinal9 and 92 species are recorded as exotics10. Habitat-wise distribution of exotic species shows a preponderance of herbs with 35 species followed by 29 species of trees, 21 shrubs and 7 climbers (Figure 2). Of the total, 7 species are found exclusively in the sacred groves11. They include Butea monosperma, Glochidion zeylanica, Hydnocarpus pentandrus, Sarcostigma kleinii, Sterculia foetida, S. guttata and Vateria indica. In addition 24 species of Pteridophytes12, 5 species of Bryophytes namely Anthoceros, Cyathodium cavernarum, Octoblepharum albidum, Porella and Riccia sp., 4 species of gymnosperms namely Araucaria, Cupressus, Cycas circinalis, and Podocarpus sp., macrofungi like Agaricus, Polyporus and crustose and foliose lichens have also been recorded. The area is facing threats of various kinds. This is mainly due to destruction of natural habitats. Invasion of alien species is a potential threat to the native flora. Biodiversity depletion is also due to climate change, increase in population and modification of land for developmental and infrastructural projects. Every step should be taken to inventorise and to document the diverse floral wealth for sustainable development. The Convention on Biological Diversity held at the Rio de Janerio in 1992 has emphasized the importance of conservation of the biological diversity and its sustainable utilization. The importance of Biodiversity conservation came into effect after the Biodiversity Act 2002. The practice of nature conservation is a very ancient tradition in India that dates back to hunting gathering stage of the society. The presences of sacred groves in the area helps in in situ conservation of not only RET species of flora but also fauna. In order to address these issues, the diversity of the area needs conservation. The conservation of the species can be done through people?s participation. Regular monitoring of the diversity is required to evaluate the change in the pattern of vegetation and floristic composition.
1. Sasidharan, N. Biodiversity Documentation for Kerala. Part 6: Flowering Plants. (2004) KFRI, Peechi, Kerala, India. 2. Manilal, K.S. & Sivarajan, V.V. Flora of Calicut. (1982) Bishen Singh & Mahendra Pal Singh, Dehra Dun. 3. Ramachandran, V.S. & Nair, V.J. Flora of Cannanore. (1988) BSI, Calcutta. 4. Rajan, R. & Venu, P. Pondicherry. In: Mudgal, V. & Hajra, P.K. (eds.), Floristic Diversity and Conservation Strategies in India. Vol. III: In the Context of States and Union Territories. Botanical Survey of India, Calcutta. (1999) 1343 - 1361. 5. Devaraj, P., Ramanujam, M.P. & Ganesan, T. Status report of Sacred Groves of Pondicherry region and Strategies for Conservation. In: Kunhikannan, C. & Singh, B.G. (eds.), Proc. Natl. Workshop Strat. Conserv. Sacred Groves. Institute of Forest Genetics and Tree Breeding, Coimbatore. (2005) 16 - 21. 6. Ramanujam, M.P., Ganesan, T., Kadamban, D., Kumaravelu, G. & Devaraj, P. Flora of Sacred Groves of Puducherry (A Pictorial Guide). (2007) Dept. of Forest & Wildlife, Puducherry. 7. Fosberg, F.R. and Sachet, H. Manual of Tropical Herbaria. Regnum Veg. 39 (1965) The Netherlands. 8. Sasikala, K., Girishkumar, E. & Krishnaveni, C. A preliminary survey of the wild edible plants of Mahe, U.T. of Puducherry. Proc. National Seminar on Recent Trends in the conservation and utilization of underutilized wild edible plants. Bharathiar University, Coimbatore. (2009a) 158 - 163. 9. Sasikala, K. & Pradeepkumar, G. Medicinal plants of Mahe - a preliminary assessment. Ecology, Environment and Conservation 18(3) (2012) 607 - 612. 10. Sasikala, K., Rahina, K. & Arisdason, W. Exotic flora of Mahe, U.T. of Puducherry. Eco-chronicle 4(2) (2009b) 265 - 271. 11. Sasikala, K., Pradeepkumar, G., Harilal, C.C. & Ravindran, C.P. Ecological and socio-economic studies of the sacred groves in Mahe with special reference to the conservation and management. (2010 -2011) Project report submitted to DSTE, Govt. of India, Puducherry. 12. Nimmi Chandran, Sasikala, K. & Pradeepkumar, G. Pteridophytic flora of Mahe U.T. of Puducherry, India. Phytotaxonomy 13 (2013) 72?74.