RESEARCH ARTICLE

SPECIES DISTRIBUTION, DIVERSITY AND PRESENT STATUS OF MANGROVES IN THE NORTH AND EAST COASTS OF SRI LANKA

Abstract

Mangroves have unique characteristics to survive in intertidal environments in tropical and sub-tropical countries and they support verity of associated faunal and floral communities. They often exhibits striking zonation pattern of tree species across the intertidal zone. Mangroves are considered to have originated after the first angiosperms, around 114 million years ago. Mangroves have some unique characteristics to survive in hard environmental conditions in intertidal zones, mostly in tropical countries. This study was conducted from June, 2012 to June, 2015 along the coastal zone of the Eastern Province and Northern Province from Okanda to Modaragan Aru of the Southern boundary of Mannar District. Approximate length of the study area was 786 km. The total study area was completely in the dry zone of the country and covered seven administrative districts namely; Ampra, Baticaloa, Trincomalee, Mullathiv, Jaffna, Kilinochchi and Mannar. According to the Department of Forest Conservation, Sri Lanka, the mangrove area of North and Eastern province is 11,866 ha. Highest extent of mangroves were found in the Jaffna district (2,505 ha) and the lowest was recorded in the Ampara District (618 ha). The study area included 76 % of the total mangrove area along the 753 km of the coastal belt in the North and Eastern Provinces. Eighteen out of 21 true mangrove species has been recorded from the study area during this survey. This represent ~ 86% of total mangrove species recorded in Sri Lanka. Majority of mangroves (86 %) are present in the dry zone of the country. Four species are common and seven species are very rarely recorded in dry zone including one critically endangered species. Three species are confined only to the wet zone or the intermediate zone of the country. According to the findings some species of mangroves shows geographical isolation due to climatic variations.

The accurate species composition of the country is still uncertain as even one new mangrove species has been recorded recently. Also, the mangrove species present at each mangrove patch also need to be assessed in order to support future conservation and management plans. Distribution of very common, common, rare and very rare mangrove species around the country is also unknown and this has affected formulating special management plans

Keywords: Mangroves, distribution, abundance, relative density, relative frequency, conservation, management

How to Cite: Prasanna,M.G.M, Ranawana,K.B,Jayasuriya,K.M.G.G,Abeykoon,R.H.M.P, Ranasinghe,M.S, (2017). SPECIES DISTRIBUTION, DIVERSITY AND PRESENT STATUS OF MANGROVES IN THE NORTH AND EAST COASTS OF SRI LANKA.WILDLANKA, 5(3):Pages 090-098

Published On:2017-09-30

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