Analisis Kerapatan dan Tutupan Kanopi Mangrove di Gili Petagan, Lombok Timur

Abstract

Ekosistem mangrove terdapat pada daerah peralihan antara daratan dan lautan yang dapat berkembang pada daerah pasang surut dengan substrat berlumpur atau berpasir. Ekosistem mangrove mempunyai fungsi fisik, ekologi, dan ekonomi. Gili Petagan merupakan salah satu pulau kecil yang terletak di Desa Padak Guar, Kecamatan Sambelia, Kabupaten Lombok Timur dengan luas 56,8 hektar dan didominasi oleh vegetasi mangrove. Penelitian ini bertujuan untuk mengetahui kerapatan dan tutupan kanopi mangrove di Gili Petagan, Kecamatan Sambelia, Kabupaten Lombok Timur. Pengumpulan data kerapatan mangrove menggunakan metode Dombois & Ellenberg, sedangkan data tutupan kanopi mangrove menggunakan metode hemispherical photography. Hasil penelitian ditemukan empat jenis mangrove yaitu Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, dan Sonneratia alba. Kisaran diameter batang mangrove di Gili Petagan yaitu antara 4,7-9,56 cm dengan kisaran basal area yaitu antara 46,66-5.320 m²/ha. Rata-rata kerapatan mangrove sebesar 3.120 ind/ha, termasuk dalam kriteria baik. Kemudian nilai rata-rata tutupan kanopi mangrove sebesar 71%, termasuk dalam kategori sedang. Jenis substrat yang dominan ditemukan pada Gili Petagan yaitu lempung berpasir yang sesuai untuk pertumbuhan mangrove. 

The mangrove ecosystem is found in transitional areas between land and sea that can develop in tidal areas with muddy or sandy substrates. Mangrove ecosystem have physical, ecological and economic functions. Gili Petagan is a small island located in Padak Guar Village, Sambelia District, East Lombok Regency with an area of 56.8 hectares and is dominated by mangroves. This study aims to determine mangrove’s density and canopy cover in Gili Petagan, Sambelia District, East Lombok Regency. Mangrove density data were collected using the Dombois and Ellenberg method, while data on mangrove canopy cover were obtained using the hemispherical photography method. The result of the study found four mangrove species, Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, and Sonneratia alba. The range of mangrove trunk diameters on Gili Petagan is between 4.7-9.56 cm with a basal area range of between 46.66-5,320 m2/ha. The average density of mangrove is 3.120 ind/ha, which falls within the "good" criteria. Furthermore, the average value of mangrove canopy cover is 71%, classified as "moderate." The dominant type of substrate found on Gili Petagan is sandy loam which is suitable for mangrove growth.