Factors influencing community mangrove planting success on Manus Island, Papua New Guinea.
This study evaluates the factors affecting community mangrove restoration at nine sites in eight different coastal villages of Manus Island, Papua New Guinea. Between June 2012 and April 2014, more than 8,400 mangrove seedlings of five species were planted on both restoration sites and sites with no history of mangroves. The timing of the plantings was uncontrolled, and some communities continued haphazard planting between the two periods. The success rate was highly variable and after 22 months the percentage of established plants ranged between 0 and 102%. My findings showed that the choice of genus planted, protection from wave action and the substrate were critical factors in reestablishment. Survival was highest for Rhizophora spp., at sites protected from wave action, and at locations with sand and gravel substrates. These results suggest that mangrove replanting success on Manus Island can be improved by preselecting sites and restricting plantings to Rhizophora spp.