Mangrove species structure at the Tuntang Estuary, Demak, Central Java

Abstract

Abstract The Tuntang estuary is located in the coastal area of the Demak Regency, which has a considerable mangrove ecosystem potential. However, their persistence is degraded due to land conversion, deforestation, and climate change. Hence, to provide the basis for mangrove conservation in that area, it is essential to gain insight into the mangroves’ composition and structure. Vegetation data were obtained by using a quadratic transect survey method with plot sizes for categories of the tree (10x10 m), sapling (5x5 m), and seedling (2x2 m). The results showed that eleven true mangroves and three mangrove-associated species were found in the mangrove ecosystem of the Tuntang estuary. All true mangrove species are included in the International Union for Conservation of Nature and Natural Resources (IUCN) Red List of threatened species. The dominant species was Rhizophora mucronata, which showed the most significant important value index of each growth stage. The research area’s biodiversity and dominance index were categorized as very low, but the evenness index was relatively high. The standing structure in the reverse “J” shape is formed by the number of trees and regeneration ratios. The vulnerability to degradation level on density and dominance index parameters was low, while the diversity index parameter was classified as moderate, which displays a potential vulnerability to disturbances. This study highlights that conserving mangrove ecosystems on the coast around the Tuntang estuary is essential to defend the coastal area from abrasion and tidal flooding, which have been problems in the area for long periods.