A comparative study on mangrove community structure at Karimunjawa, Indonesia: Kemujan Island and Jati Kerep aquaculture area

Mangrove forest habitats of great variety can be found in the Karimunjawa Islands, which is located in Indonesia. The Karimunjawa Islands, located in Jepara Regency, is a group of 27 islands in the Java Sea. Mangrove is a type of vegetation that protects coastal habitat. The ecosystem’s long-term sustainability will be determined by its regeneration condition. This study aimed to examine mangrove community structure and mangrove regeneration at Karimunjawa. The study area was determined by purposive sampling technique with plot at size of 10 x 10m for tree, 5 x 5m for sapling, and 1 x 1m for seedling. This study revealed 11 mangrove species with the highest IVI value of 63.60% for R. stylosa at Kemujan Island, and L. racemosa with an IVI value of 109.71% at Jati Kerep Aquaculture Area. The diversity index (H’) was ranging between 1.55 to 2.00 and both study areas shared high similarity (SI = 70.59%). It was revealed that mangrove species grow at a slightly slower pace in Karimunjawa, as indicated by the number of individual number of seedlings (179 ind/ha) < sapling (234 ind/ha) < tree (239 ind/ha). Further test using one-way analysis of variance (ANOVA) revealed that there was a non-statistically significant difference in mean between Kemujan Island and Jati Kerep Aquaculture Area (F(1,4) = [3.136], p = 0.151).