Vegetation analysis of Sungai Tembiluk Sungai Air Mata mangrove forest: a proposed site of Ketapang Botanical Garden in west Kalimantan

The mangrove forest of Sungai Tembiluk ̶ Sungai Air Mata is a High Conservation Value (HCV) area composed of native plants of Ketapang Regency, West Kalimantan, which is proposed as Ketapang Botanical Garden. This study aims to analyze the vegetation composition, Important Value Index (IVI), species richness, diversity, and evenness in the mangrove forest of Sungai Tembiluk ̶ Sungai Air Mata that could be used as the basis of sustainable management practices. Thirtyone plots of 10x10 m laid down along the transect and 10 mangrove species were identified. Seedlings were dominated by Bruguiera gymnorhiza (IVI = 109.83%), while sapling and tree were dominated by Rhizophora apiculata (IVI = 160.79% and 163.28%, respectively). The Margalef Richness Index (D) was 1.11 (low), the Shannon Diversity Index (H') was 1.08 (moderate), and the Pielou Evenness Index (J’) was 0.47 (moderate). The horizontal structure was an L ̶ form, which meant as the diameter class getting bigger and the number of species was becoming fewer. The vertical structure had four canopy layers, namely stratum B, C, D, and E. The plant diversity information of this region is essential as a starting point for the development of Ketapang Botanical Garden in order to maintain and improve the initial environmental conditions and native plant species composition