Species composition, biomass and carbon stocks, anthropogenic influences of pristine mangroves in Urani, Kottugal mangrove reserve forest

Abstract

Mangroves are a group of plants that grow in inter-tidal zones in tropical and subtropical latitudes. Most of the mangroves are trees and shrubs which contain leathery and broad, evergreen leaves. About 15,670 ha of mangrove habitats are scattered along the coastal zone of Sri Lanka. From that Eastern province shares 28% of the mangrove cover. Since they were highly isolated during the last three decades because of the civil war, there are limited research publications related to mangroves in this part of the country, especially about mangrove habitats Ampara District. The present study was conducted at Urani Kottugal mangrove reserve forest in the Ampara district, the eastern coast of Sri Lanka with the objectives of reporting the present Species composition and estimating the capacity of the aboveground and belowground biomass with carbon stocks. This may be the first time specifically scientific records about the Urani Kottugal mangrove reserve forest in recent history. We used belt transects in width laid perpendicular to the shoreline and across the water-land gradient for the mangrove vegetation survey. True mangrove species in each transect were identified and counted. DBH (Diameter at Breast Height) and height were recorded and determined above and belowground biomass as well as carbon stock using published allometric equations and a conversion factor, respectively. Four true mangrove species were recorded in the Urani Kottugal mangrove reserve forest. Out of that, the highest species composition was recorded in Excoecaria Agallocha. The species Bruguiera Gymnorhiza was a critically endangered mangrove species recorded in study área. The results showed that the values of above-belowground biomass were 24.5072 Mg ha-1 and 8.4854 Mg ha-1. The above-ground biomass is stored more than the below-ground pool. Infrastructure development and selected mangrove replanting programs directly influenced the biogeography of species there. More research is needed to understand the ecological aspects of theses mangroves. It is recommended that government should take immediate action to prevent distractive anthropogenic activities in this mangrove ecosystem.