Mangrove Network Sri Lanka
Ecological Mangrove Restoration – Workshop Series from 5 to 9 February and from 12 to 15 February 2007 in the National Aquatic Resources Research & Development Agency Center (NARA)
The organisation Mangrove Action Plan (MAP) and the Sewelanka Foundation implemented two workshops regarding Ecological Mangrove Restoration (EMR) in Sri Lanka. Many staff from NGOs in Sri Lanka participated in the workshops. Staff members of the GNF partner organisation EMACE, who tend to the mangrove restoration at Bolgoda Lake, were also among the participants.
Current studies have revealed that one hectare of mangrove forest can have an uptake of about 3.2 tonnes carbon dioxide per annum, with which they greatly contribute towards CO2 reduction. Over the last years, our planet has lost 255,000 hectares of mangrove forests.
MAP´s focus is on conserving natural mangrove forests using various approaches. Implemented methods are the conservation of the existent forests, environmental education, sustainable use of mangrove forests, community-based mangrove management and mangrove restoration. The workshops focused mangrove restoration, since there have been numerous examples of pre- and post-tsunami failures in this area.
MAP promotes a six-step method to successful mangrove restoration called "Ecological Mangrove Restoration (EMR)". The key points of this method are:
- Understanding of both, the autecology (individual species ecology) and community ecology of mangrove species in site, paying particular attention to patterns of reproduction, propagule distribution and successful seedling establishment.
- Understanding the normal hydrologic patterns that control the distribution and successful establishment and growth of targeted mangrove species.
- Modifications assessments of the previous mangrove environment that currently prevents natural secondary succession.
- Selecting of an appropriate mangrove restoration site through application of steps 1 to 3 above, that is both technically likely to succeed in rehabilitating a healthy mangrove ecosystem and also takes into consideration resolution of land use issues in order to ensure long-term conservation.
- Designing restoration programmes at appropriate sites selected in step 4 above, to initially restore the appropriate hydrology of the site and take advantage of natural volunteer recruitment of mangrove propagules for plant establishment.
- Utilizing the actual planting of propagules, collected seedlings, or cultivated seedlings in the case that after completing steps 1 to 5 above, natural recruitment does not provide the quantity of successfully established seedlings, rate of stabilization or rate of growth of saplings established as quantitative goals for the restoration project.
Under the aspect of this six steps, excursions to different areas were undertaken after the theoretical part of the workshops. Six restoration sites were visited, located in southern and eastern lagoons. At all sites, the mangrove seedlings (Rhizophora spp.) were cultivated in nurseries and planted regardless of their habitat requirements. Normally ecosystems in lagoons have a very narrow tolerance margin in which mangroves survive. Their tolerance towards floods depends directly on the water depth and the concentration of fresh water entering the lagoon seasonally. As a result, seedlings were planted in areas of sub-optimal water depth.
The aims of the mangrove network are the regular exchange of experiences and results and inclusion of decision makers and the local population into sustainable management plans.
Further information in English can be found in the following pdf-file as a downloadable Handbook of the Workshop Series "Ecological Mangrove Restoration"