International Journal of Research in Social Sciences Vol. 9 Issue 1, January 2019, ISSN: 2249-2496 Impact Factor: 7.081 Journal Homepage: http://www.ijmra.us, Email: [email protected] Double-Blind Peer Reviewed Refereed Open Access International Journal - Included in the International Serial Directories Indexed & Listed at: Ulrich's Periodicals Directory ©, U.S.A., Open J-Gage as well as in Cabell’s Directories of Publishing Opportunities, U.S.A An Assessment of Floral Diversity in the Mangrove Forest of Karaikal, Karaikal District, Puducherry Union territory Duraimurugan, V.* Jeevanandham, P.** Abstract The tropical coastal zone of the world is covered by a dynamic system in a state of continual adjustment as a result of natural process and human activities. The mangrove ecosystem is a unique association of plants, animals and micro-organisms acclimatized to life in the fluctuating environment of the tropical and subtropical and intertidal zone covering more than 10 million ha worldwide. The present study documents the directly observed diversity of true mangroves and their associates, in the mangroves of Karaikal. The present study recorded a sum of 136 plant species. Among the plants 8 species were true mangroves and 128 species were mangrove associates. The family Rhizophoraceae is the dominant group represent three species followed by Avicenniaceae with two species. The associated mangrove flora recorded in the present study falls to 128 genera belongs to 42 families from 20 orders. As per IUCN current status, most of the mangrove species in decreased status. The base line information is very much helpful for the conservation and feature references. Key words: Avicenniaceae, Flora, Karaikal, Mangrove, Rhizophoraceae. * P.G. and Research Department of Zoology and Wildlife Biology, A.V.C College (Autonomous), Mannampandal, Mayiladuthurai Tamil Nadu, India,– 609 305,. ** Department of Zoology, TBML College, Poraiyar, Tamil Nadu, India 609 307. 457 International Journal of Research in Social Sciences http://www.ijmra.us, Email: [email protected] ISSN: 2249-2496 Impact Factor: 7.081 Introduction As per Pritchard [23] statement an estuary may be defined as a semi-enclosed coastal body of water which has a free connection with the open sea and within which sea water is measurably diluted by fresh water from river and land drainage. At the same time the fresh water carrying the fertile silt and runoff from the land. Estuary is always a home for unique floral and faunal community of the world. The estuaries always have a unique feature of physical and chemical nature, in connection with their shape, catchment area, connection to the sea and tidal regime of the area [11][4]. The growth and distribution of floral community will be determined by the salinity and the amount of flooding [22],[21] of the estuarine marshes and marine ecosystem. Estuaries support different microhabitats, such as mangroves, salt marshes, sea-grass, mudflats etc. The algal groups and seagrasses are more towards the sea coast of the estuaries. The mangrove plants are well adapted near the mouth of the rivers and deltas. Estuaries contribute particularly priceless protection beside the stormy waters of the sea and also providing a protected haven for the thousands of livings that use estuaries as, feeding and breeding grounds. Mangroves are represents a characteristic littoral, evergreen forest of the estuary ecosystem and in fact form an icon for the estuarine ecosystem(https://www.pmfias.com / mangrove-estuarine-ecosystems/) [28] The extensive development of mangroves depends on a layer of sand or earth, normally deposited by action of rivers and high flood tides and shores, free of strong wave and tidal actions of the sea. It also required slat marine water and brackish water [33]. The shorelines of tropical regions of the world have best developed mangroves between the high and low tide regions [29]. The great mangrove forest formations are naturally grow in the privileged muddy shorelines that are frequently connected with the formation of deltas at the mouth of a riverine system [9]. The evergreen mangroves grows not only in the estuarine habitats, it can also be growing on sandy and rocky shores, coral reefs and oceanic islands. For an instance where islands can be completely surrounded by mangroves, it is not possible to describe a typical mangrove, as the differences in the girth and height, within the same species, is immense, depending on the many environmental and other factors that control growth [19],[5]. Mangroves are trees and shrubs fall into two groups according to their habitats in nature: true mangroves and mangrove associates. The river Arasalaru estuary mangroves acts as a sink for sewage discharges. Conservation priorities and restoration measures must be decided based upon the inventorisation of biological diversity [13]. The floral groups which border the estuaries are exceedingly tailored to a dynamic ecosystem. The estuarine environments experience daily changes due to tidal influences of the sea, and seasonal changes due to rainfall and river flow regimes [20]. Vegetations play an indispensable role in the maintenance of a biologically balanced and healthy waterway [34][36]. It gives an extensive range of functions that are essential for supporting the floral and faunal life and for maintaining the value of the ecosystem. These functions include: flood control; shoreline stabilisation; sediment, nutrient and pollutant filtering and, most importantly, the provision of food, shelter and breeding habitats for a wide range of organisms [34]. Hence the botanical assessments, such as floristic composition and structure are essential to understand the extant of phytodiversity of any ecosystem [36]. Hence, the present study was carried out to document the plant diversity of the karaikal mangrove. 458 International Journal of Research in Social Sciences http://www.ijmra.us, Email: [email protected] ISSN: 2249-2496 Impact Factor: 7.081 MATERIALS AND METHODS The present investigation was carried out in mangrove forest at Karaikal (10.93oN and 79.83oE) of Puducherry Union Territory, Southeast coast of India between January 2015 and December 2015. The area of Karaikal region is 161 sq. km which is about 150 km from the south of Puducherry Union Territory and is surrounded by Nagapattinam district of Tamil Nadu. This district consists of almost entirely coastal alluvial soil which is highly suitable for cultivation of paddy and pulses. The planted mangrove of Karaikal is situated in the tri junction of River Arasalaru, Bay of Bengal and Beach of Karaikal. This mangrove forests was established by M.S. Swaminathan Foundation and with the help of Department of Tourism and Development, Forest and Wildlife and Fisheries of Puducherry during 2009-10 (10 ha). Currently, the area of mangroves is 32. 3ha. The mangroves plantation is surrounded by human settlements and opens into fishing areas of Bay of Bengal. The mangroves receive marine water from the Bay of Bengal and fresh water from the River Arasalaru and other small tributaries of the river Cauvery. The small channels running across Karaikal town are also bringing the sewage and household wastes into the mangrove ecosystem. Data Collection Field surveys were regularly undertaken in and around the Karaikal mangrove forest from January 2014 and December 2017. Plants either with flowers or fruits were collected and photographed, and identified or confirmed with available regional floras [8][15]-[17] [14], revisions [24],[6],[4],[7],[1] and monographs [32],[30],[31][10]. Families are arranged according to Phylogeny Group III Classification [2]. Abbreviations of authors’ names of plant names strictly follow Brummitt and Powell [3]. The current nomenclature of all taxa was further determined by referring to authentic databases, such as International Plant Names Index (IPNI), The Plant List and Tropicos. The Global Biodiversity Information Facility—is an international network and research infrastructure funded by the world’s governments and aimed at providing anyone, anywhere, open access to data about all types of life on Earth is also used to identify the species and conformations. E-flora of karaikal is also used to identify the species. Results and Discussion A Sum of 136 plant species were recorded/ identified during the study period. These flora were classified into two groups as true mangrove and mangrove associated flora. Eight mangrove species were recorded in the study area (Table 1). The family Rhizophoraceae is the dominant group represent three species followed by Avicenniaceae with two species. The family Euphorbiaceae and Acanthaceae represent one species each. According to International Union for Conservation of Nature and Natural resources status all the mangrove plants are coming under ―Least concern‖ group. As seen in plate1,2 medium sized trees (Avicennia officinalis L, Rhizophora mucronata Lam and Bruguiera cylindrica L.) were the dominant groups, followed by big trees (Avicennia marina (Forsk.) Vierh and Rhizophora apiculata Blume). Derris trifoliata Lour, Excoecaria agallocha L and Acanthus ilicifolius represented small tree and shrub respectively. In West coast of kerala 15 true mangrove species were recorded by [34] belonging to 9 genera and 6 families. The family Rhizophoraceae dominanat represented with 7 species in west coast of Kerala[34] , which shows the newly emerged mangrove of Karaikal also support the Rhizophoraceae as dominant. 459 International Journal