Spatial distribution of mangrove health index on three genera dominated zones in Benoa Bay, Bali, Indonesia

Abstract

Abstract. Sugiana IP, Andiani AAE, Dewi IGAIP, Karang IWGA, As-Syakur AR, Fharmawan IWE. 2022. Spatial distribution of mangrove health index on three genera dominated zones in Benoa Bay, Bali, Indonesia. Biodiversitas 23: 3407-3418. A study of mangrove forest stratification was conducted in Benoa Bay which experienced high coastal development pressures during the last decade. The study aimed to determine mangrove health index distribution (MHI) and forest community structures along three genera-dominated zones which were Sonneratia, Rhizophora and Bruguiera. Random forest method was applied to classify the areas of distributed genera along the bay. Forest structure was assessed with 54 plots. The forest was mainly composed of Rhizophora and Sonneratia-dominated zones in a respective forest area proportion at approximately 51% and 45%. Those zones were dominated by R. mucronata and S. alba with an importance value index (IVI) at 266.35% and 145.57%, respectively. A narrow Bruguiera zone composed of B. gymnorrhiza domination was found in the most landward area, only covering 4% of the mangrove area. Overall accuracy and a kappa coefficient indicated high accuracy of forest classification at 97% and 0.94 respectively. We found that 47.44% of mangrove areas could be classified into the highest healthiness category indicating that the mangrove forest in Benoa Bay is in excellent condition. The Rhizophora zone made a significant contribution to the entire forest state since the excellent category coverage in this zone was approximately 73.80%.

Mangrove zonation, community structure and healthiness in Kei Islands, Maluku, Indonesia

“…Five genera-dominated zones were identified from the estuarine habitat, while only three obvious patterns of mangrove-occupied oceanic habitat were recorded. The number of genera-dominated layers in this study was higher than the estuarine mangrove in Benoa Bay, which was composed of three mangrove zones (Sugiana et al 2022). Another study in an archipelagic area of Papua found three zones along the mangrove area perpendicularly from landward to seaward (Nurdiansah and Dharmawan 2021a).…”

Pemetaan kondisi hutan mangrove di kawasan pesisir Selat Madura dengan pendekatan Mangrove Health Index memanfaatkan citra satelit Sentinel-2

“…Analisis spasial MHI dilakukan dengan menggunakan kombinasi 4 index vegetasi berdasarkan persamaan yang dikembangkan oleh Nurdiansah & Dharmawan (2021). Formula perhitungan yang sama juga digunakan pada penelitian lainnya antara lain Sugiana et al (2022) dan Dharmawan (2021). Secara umum terjadi perbaikan kondisi hutan mangrove berdasarkan nilai MHI di kawasan pesisir Surabaya dan Sidoarjo.…”

“…Tidak adanya ancaman pembalakan liar, konversi lahan dan reklamasi pantai memungkinkan hutan mangrove tumbuh semakin luas. Jika dibandingkan dengan penelitian serupa yang dilakukan di Teluk Benoa Bali (Sugiana et al, 2022) dapat dinyatakan bahwa berdasarkan perhitungan MHI, maka kondisi hutan mangrove di pesisir Surabaya dan Sidoarjo menunjukkan trend yang lebih baik. Penurunan kualitas hutan mangrove di Teluk Benoa terpantau dari semakin bertambahnya luasan dengan kelas MHI buruk.…”

“…Kondisi tersebut diperkirakan akibat fenomena dieback. Fenomena ini adalah kematian massal vegetasi mangrove secara gradual yang ditandai dengan menurunnya prosentase tutupan kanopi akibat gugurnya daun mangrove dalam jumlah yang besar (Nguyen et al, 2021;Sugiana et al, 2022). Tingginya sedimentasi akibat reklamasi pantai menjadi penyebab utama fenomena tersebut.…”

Spatial distribution of carbon dioxide (CO2) and nitrous oxide (N2O) concentrations across three mangrove zones in Ngurah Rai Grand Forest Park, Bali

“…We took three stations divided by mangrove community zones (seaward, middle and landward), during the rainy season in December 2020, with atmospheric geographical conditions in the form of temperatures ranging from 25.1°C -32.2°C (Average: 28.0°C) and rainfall of 355.5 mm in the same month [11]. Overall, three mangrove genera predominate in this area: Sonneratia, Rhizophora and Bruguiera [10,13], with an average mangrove health index condition in the moderate category [13]. Environmental factors such as the type of sediment range from fine sand to gravel with a predominance of coarse sand [14,15], as well as trends in shaft water quality (salinity and pH) which experience gradations with differences in distance from the sea [10].…”