Journal of Environmental Treatment Techniques 2015, Volume x, Issue x, Pages: 17-21 17 Reproductive Phenology of True Mangrove Species in Pichavaram Mangrove Forests, Tamilnadu, India - A Comparative account A. Arunprasath and M. Gomathinayagam* Department of Botany, Annamalai University, Annamalainagar-608002, Chidambaram, Tamilnadu, India. Received: 29/09/2015 Accepted: 17/12/2015 Published: 30/09/2015 Abstract The target of this study was to analyse various phonological characteristics and reproductive biology of mangroves in Pichavaram for developing a data bank which could be of help to forest managers in planning for regeneration of species in the forest. We collected data on number of days taken by species to flower and to produce mature propagules/seeds. We also recorded all phenophases of each species and maturity characteristic of mangrove seeds in Pichavaram forest blocks. Storage life of seeds materials for various mangrove species was also tested with the help of mist chamber design. Excoecaria agallocha and Acanthus ilicifolius take only 2-3 months to produce mature hypocotyls whereas Rhizophora mucronata, Bruguiera cylindrica and Xylocarpus mekongensis complete these phases between 4 and 6 months. 30 % of seeds of Rhizophora apiculata and Ceriops decandra germinated after a storage period of up to 45 days showing higher viability than other species. However, fresh seeds of a majority of mangrove species exhibited more than 65-94 % germination. Proper identification of period of collection, maturity characteristics and germination timings will aid in better regeneration of mangroves in Pichavaram. Keywords: Germination, Mangrove, Phenology, Pichavaram, Seeds. 1 Introduction 1 Mangrove forests are among the world’s most productive ecosystems and sustain a variety of marine and estuarine communities [1,2]. However, mangroves are also one of the world’s most threatened tropical and subtropical ecosystems and are being degraded in most countries mainly because of anthropogenic activities and unsustainable exploitation[3]. Mangroves are the only tall tree forests situated between the land and sea. [4,5] and they are tightly bound to the coastal environments in which they occur. Once established, mangroves offer recreational potential, a sustainable supply of seafood for aquatic animals and useful products for community subsistence [7]. As a primary producer, mangroves also serve as food for herbivores and detritivores. Litter-fall, consisting primarily of mangrove leaves, becomes available following leaf senescence and death. However, mangroves are also one of the world’s most threatened tropical and subtropical ecosystems and are being degraded in most countries mainly because of anthropogenic activities and unsustainable exploitation [8]. Tropical plant communities with their high level of species diversity display phonological events staggered in time and space, which are, governed both by biotic and abiotic factors[9]. The plants may either stagger their phonological activity to avoid competition for pollination and disperser agents or may opt for clumping of phenological activity to attract the pollinators and Corresponding author: M. Gomathinayagam, Department of Botany, Annamalai University, Annamalainagar-608002, Tamilnadu, India, email: gomsnayagam@yahoo.com. dispersers or to swamp the predators by producing the vulnerable organs in concentrated burst [10]. Understanding of such behaviour of the communities is useful in evolving proper management strategy. Information on phenology is useful in predicting the interactions of plants and animals to the changing environment [11]. Description of various phonological events of plants is helpful in understanding of ecosystem functioning [12]. Only a few studies have been carried out on phonological events of mangrove species in different regions of the world [13, 14]. Some earlier studies on the Orissa mangroves by [15,16] gives only limited information on flowering and fruiting periods of different species. [17] found reproductive events in mangroves were relatively synchronous among trees at particular latitude and this was constant among years. However, the reproductive status of individual trees highly varied between years. Individual trees and clusters did switch synchronously from reproductive to a non reproductive state across years. Despite the importance of mangrove ecosystems, very few studies have considered the phenology of different mangrove species [18-26]. Most phenological studies have been confined to monitoring flowering and fruiting by direct observation, and very few studies have combined direct observations with litter-fall measurements to assess the phenology of these species [27]. Phenological events in mangroves are influenced by local or regional environmental conditions, particularly day length, air temperature, rainfall and water status [28,29]. This study was carried out to investigate the Reproductive phenological events, seed viability and seed germination of mangrove tree species in Pichavaram mangrove forest. Journal weblink: http://www.jett.dormaj.com J. Environ. Treat. Tech. ISSN: 2309-1185