Studies on tidal vegetation in East Midnapore Coastal Belt, West Bengal, India

Bishnupada Jana*, Amal Kumar Mondal

Plant Taxonomy, Biosystematics and Molecular Taxonomy Laboratory, UGC-DRS-SAP & BOOST-WB Supported Department, Botany and Forestry, Vidyasagar University, Midnapur- 721102, West Bengal, India.

ABSTRACT

This research paper presents the analytical studies on tidal vegetation of Purba Medinipur district. This district is covered by a massive network of canals and Rivers including Hoogli, Rupnarayan, Haldi, Keleghi, Bagui & Rasulpur. Tidal zones of canals and estuaries of Rupnarayan, Haldi, Hoogli & Rusulpur are natural place of mangroves and mangrove associates. Total 42 species have been identified and out of theme 6 species i.e. Avicennia marina, Avicennia officinalis, Bruguiera gymnorrhiza, Ceriops decandra, Rhizophora mucronata & Sonneratia alba are mangrove plants and other 36 plant are mangrove associates. Mangroves are colonized at sea side estuaries whereas mangrove associates are found both sea side area and canal side.

Keywords: Mangroves, Mangrove associates, Estuaries, Species and Tidal vegetation

1. Introduction

Purba Medinipur is one of the 23 administrative districts of West Bengal and it is coved by reticulate river and canal system. It is situated by the Bay of Bengal and is surrounded by the Bay of Bengal and Balasore district of Odisha State in its South, Paschim Medinipur in its West, Howrah district in the North and South 24 Parganas in the East. Coastal line of Midnapore occupies 27% of total coast line in West Bengal (near about 60KM) covering Digha, Sankarpur, Tajpur, Mandarmoni, Junput, Hijli, Khejuri and Haldia (Mandal et al.,2013). Tidal zone of estuaries of rivers and canals bears distinct vegetation mainly mangroves and mangrove associates. Mangroves are defined as assemblages of salt tolerant trees and shrubs that grow in the intertidal regions of the tropical and subtropical coastlines. They grow luxuriantly in the places where freshwater mixes with seawater and where sediment is composed of accumulated deposits of mud. Mangroves are a threatened salt tolerant higher group of flowering plants (Naskar and Mandal, 1999) that occur in relatively sheltered areas along estuaries, coastal lagoons and backwaters. They are generally inundated and exposed during regular high and low tides respectively, and are nurtured by a mixture of fresh water from rains and land drainage with coastal marine waters (Banerjee et al., 2002). Typical mangrove species usually have pneumatophores or breathing roots (negative geotropic root), stilt roots, knee roots, viviparous germination, xerophyllous leaves and salt excretory glands (Tomlinson, 1986).

2. 1

   METHODS AND MATERIALS

This was totally field based research work. Field survey and field study are two methods which are applied to construct this article. Frequent field study all over coastal area, canals and rivers sides were continued in every month from the year 2014 and onwards. Direct observation of vegetation was done for identification and better  understanding of the special peculiarities of complex coastal vegetation of Midnapore. Under the supervision of my Ph.D. guide all procedure has been conducted. This research work is totally self financed, self interested and dedicated programme for enhancement my career.  Nicon Cool Pix L120 camera and Germen eTrex GPS detecting instrument were handled for proper data collection.  Notable specimens were collected making herbarium specimen for further reference.

3. RESULT AND DISCUSSION

After completion of my target field study 42 tidal plant species have been identified in which 6 species are mangroves and rest of 36 species are mangrove associates this proportion is presented in pie-chart no-1. Six listed mangrove species are found only in tidal zone. Out of 36 mangrove associates 17 species are exclusively tidal mangrove associates and grown in mud of tidal flat and other are distributed terrestrial habitat which is flooded at high tide. All 42 plant species, their families, habitat and characters are listed in table No-1. In table No-2 only mangrove plant species, their families and characters are listed. Table No-3 bears exclusively tidal mangrove associates with their families and characters. Pie-chart No-2 indicates the proportion of mangrove and exclusively tidal mangrove associates.

Mangrove species are grown only moderate salt containing marshy tidal area especially cannel side and estuary points. High salt containing sandy coastal side is not suitable for mangrove species habitat. So, in study area except estuary point, cannel side and tidal flat mangrove species does not show their existence. Tidal flow, moderate salt containing muddy soil is suitable for mangrove species occurrence.

4. CONCLUSION

Mangroves and mangroves associates are the tidal vegetation. Further research is needed on the medicinal value, ecological value, socio-economic value and conservation of many threatened plant species of coastal area of studied district. Various anthropogenic activities i.e. hotel industry, tourism, dry fish industry, fishing activities, grazing etc.  are the main causes to destroy the tidal vegetation. East Midnapore tidal vegetation is a golden treasury of natural flora. Also adaptation variation among these plant species may be subject of next research.

5. ACKNOWLEDGEMENT

I am grateful to my parent. I also grateful Dr. Debdulal Banerjee, Associate Professor of Botany & Forestry, Vidyasagar University. Also I give thanks to all research scholars of my laboratory for continuous help.

REFERENCES               

1. Banerjee, L.K., Rao, T.A., Shastry, A.R.K., & Ghosh, D. (2002). Diversity of Coastal Plant Communities in India. Kolkata: ENVIS-EMCBTAP, Botanical Survey of India, Ministry of Environment and Forests. 524 pp.
2. Mandal, M., Dandapath, P. K., & Bhushan, S. (2013). Digha Sankarpur littoral tract a geographical case study. International Journal of Humanities and Social Science Invention, 2(4), 46-54.
3. Mandal, R. N., & Naskar, K. R. (2008). Diversity and classification of Indian mangroves: a review. Tropical Ecology, 49(2), 131-146.
4. Tomlinson, P. B. (1986). the Botany of Mangroves Cambridge University Press London.