Restoring lost mangroves – Lessons from Philippines

One of the world's most intensive efforts to restore coastal mangrove forests was in Philippines where extensive tracts of mangroves were converted to fish farms. The restoration efforts are failing in many places. Biologists Maricar Samson and Rene Rollon of the University of the Philippines in Quezon City have come out with a paper titled “Growth Performance of Planted Mangroves in the Philippines: Revisiting Forest Management Strategies” in the latest issue of journal Ambio, outlining the reasons for this failure. It has relevance for other areas also. According to the researchers there was a widespread tendency to plant mangroves in areas that are not the natural habitat of mangroves, converting mudflats, sandflats, and seagrass meadows into often monospecific Rhizophora mangrove forests. Of the few that survived, the young Rhizophora individuals planted in these nonmangroves and often in low intertidal zones had dismally stunted growth relative to the corresponding growth performance of individuals thriving at the high intertidal position and natural mangrove sites. Unsound practices in some areas disturbed or damaged otherwise healthy habitats. The researchers argue that a more rational focus of the restoration effort should be the replanting of mangroves in the brackish-water aquaculture pond environments, the original habitat of mangroves preferably in gently sloping hill bottoms that are above mean sea level and flooded by the tides less than one-third of the time. The paper underscores the need for understanding the ecological needs and biology of the mangrove trees before plunging in to extensive planting activities.