Applying landscape approach in assessing effectiveness of mangrove conservation in Ca Mau Cape National Park, Vietnam

The study aims to assess the effectiveness of mangrove conservation in Ca Mau Cape National Park (CMCNP) during 1973-2018 using remote sensing and landscape metrics. The maximum likelihood method was used to classify time-series Landsat images with overall accuracy ranging from 87.8% to 90.3% and Kappa from 0.83 to 0.88. Additionally, landscape structure which expresses the spatial pattern and the connections between landscape elements such as number, size, and shape were assessed using landscape metrics including Number of patches, Landscape Shape, Largest Patch, Cohesion, Core, Contiguity, and Contagion index. The results showed that mangroves increased by 1,078 ha (7%), and the landscape structure was simple in the first period (1973-1979). In the second period (1979-2003), mangroves decreased by 1,411 ha (9.2%) during 1989-1995, and then they increased by 4,564 ha (29.9%) from 1995 to 2003. The landscape structure was fragmented, disconnected, and had irregular shapes during the beginning but improved at the late phase. In the third period (2003-2018), mangroves increased by 1,596 ha (10.5%). In which, dense mangroves increased by 2,500 ha (16.4%). And sparse mangroves decreased by 904 ha (5.9%). The landscape structure was more homogenous and connected than the second period. Since CMCNP was established in 2003, mangroves have enlarged year by year. The landscape structure became more aggregated. These proved the effectiveness of mangrove conservation in both quality and quantity.