THE DIVERSITY AND REGENERATION OF MANGROVE ON PANJANG ISLAND JEPARA CENTRAL JAVA

Abstract

Panjang Island is a small island under the administrative territory Jepara Regency, Central Java Indonesia. Small islands, such as Panjang, have been vulnerable to changes and environmental pressures. Because of their natural resources and fragile nature, the existence of small islands is necessary to be protected and ensured. Mangrove is a vegetation with a function to protect the coastal ecosystem. Its regeneration status will determine the sustainability of the ecosystem. This study aimed to assess mangrove species diversity and mangrove regeneration on Panjang Island. The site research was determined by purposive sampling. Research sites were four stations located in the southern, eastern, northern, and western part of the island. Each station occupied with three plots measuring 20 × 20 meters for tree stage, 5 × 5 m for sapling and 1 × 1 m for the seedling stage. Data was calculated according to important value index (IVI), diversity index (H') and the evenness index E . In Panjang Island, 7 true mangrove and 7 mangrove associated species have been found. The dominant true mangrove was Pemphis acidula, whereas the dominant mangrove associate was Thespesia populnea. The diversity index mangrove species (H') is between 1.28 – 1.82. The mangrove regeneration in Panjang Island did not take place appropriately, as indicated by the number of individual saplings (57 individuals/Ha) < number of individual seedlings (191 individual/Ha) < number of individual trees (274 individuals/Ha). There were two important tree species in Panjang island, Pemphis acidula (Stigi) with Least Concern status according IUCN, and Excoecaria agallocha. Both species require protection. The study recommended a mangrove reforestation with local species in order to obtain the sustainability of coastal ecosystem in Panjang Island. Keywords: Small island; Diversity; Sustainability; Regeneration; Important Value Index (IVI).