Survey on the success of mangrove restoration in Sri Lanka

Abstract

Mangrove ecosystems in Sri Lanka are decreasing at an alarming rate, regardless of the awareness on their economic uses and ecological services. Mangrove restoration received a lot of attention in Sri Lanka, particularly after the tsunami in 2004 due to their role in buffering action against tsunami. The main objective of the study was to investigate mangrove restoration success along with major prevailing stress factors and disturbances in Sri Lanka. All the lagoons and estuaries along the coastline

of Sri Lanka were examined and observations and interviews with

information was gathered from visual relevant parties in each site visited.

Rhizophora sp. has mainly been used for replanting (72%) and in this study, twenty one (21) restored sites encountered. However, only two sites i.e. Kalpitiya and Pambala showed success rates higher than 70% and Mannar showed the third highest success rate of 33%. Post planting care was the major reason for their success. Cattle trampling (100%), browsing (100%), algal accumulation (77%), insect attacks (95%), prolonged inundations or floods (27%), infestation by barnacles (14%) were observed as common

reasons for the poor success in the Starting restoration projects with

unsuccessful and less successful sites. sound scientific knowledge on the

autecology of the planted species and on the factors responsible for failures in previous efforts and regular maintenance of the site being restored at least during the first few years are recommended as solutions to avoid poor success rates.