Stok Karbon Organik Sedimen Mangrove di Laguna Segara Anakan

Abstract

Konsentrasi CO2 yang meningkat menyebabkan perubahan iklim dunia. Mangrove memiliki kontribusi besar sebagai penyerap karbon dari atmosfer di lingkungan pesisir dan menyimpannya dalam sedimen maupun biomassa. Penyimpanan karbon dalam sedimen dipengaruhi oleh sumber (termasuk jenis spesiesnya) dan perubahan faktor lingkungan sehingga menyebabkan adanya fluktuasi. Dengan ditemukannya 26 spesies mangrove pohon dan 5 spesies understorey (Aegiceras corniculatum, Avicennia alba dan Nypa fruticans) di Laguna Segara Anakan, maka  perlu dilakukan penelitian terkait pola variasi stok karbon secara spasial dan temporal (vertikal). Penentuan lokasi stasiun berdasarkan peta stratifikasi tutupan mangrove, yaitu kelas mangrove pohon, mangrove nypa, vegetasi mangrove mix dan mangrove understorey. Parameter yang diukur yaitu karbon organik sedimen, ukuran butir sedimen, dan pasang surut. Karbon organik dianalisis menggunakan metode Lost on Ignition (LOI), ukuran butir sedimen dengan particle size analyzer, dan pasang surut diperoleh dari Badan Informasi Geospasial. Hasil penelitian menunjukkan stok rerata karbon organik pada kelas vegetasi mix yaitu 366,783 ton/ha, kelas mangrove understorey sebesar 343,747 ton/ha, kelas mangrove nipah sebesar 298,002 ton/ha dan kelas mangrove pohon sebesar 264,108 ton/ha. Variasi nilai tersebut dipengaruhi oleh ukuran butir dan jenis mangrove. Hasil penelitian ini akan bermanfaat dalam pertimbangan jenis mangrove yang ditanam sebagai bahan kajian dalam mitigasi perubahan iklim global.   The increasing concentration of CO2 is causing global climate change. Mangroves have a major contribution as carbon sequestration from the atmosphere in coastal environments and stored it in sediments and biomass. The storage of carbon in sediments is influenced by environmental factors and their sources (including the type of species), causing carbon fluctuations. With the discovery of 26 tree mangrove species and 5 understorey species (Aegiceras corniculatum, Avicennia alba, and Nypa fruticans) in Segara Anakan Lagoon, it is necessary to conduct research related to the pattern of spatial-vertical variation of carbon stocks. The selection of stations was based on a stratification map of mangrove cover, namely tree mangrove, nypa mangrove, mixed mangrove vegetation, and understorey mangrove. Parameters measured included organic carbon and sediment grain size using the Lost on Ignition (LOI) method and a particle size analyzer. Tidal data was obtained from the Geospatial Information Agency. The results showed the average stock of organic carbon vertically in the mixed vegetation class was 366.783 tonnes/ha, the understorey mangrove class was 343.747 tonnes/ha, nipah mangrove class was 298.002 tonnes/ha and the tree mangrove class was 264.108 tonnes/ha. The variations in values are influenced by grain size and mangrove type. The variation in value is influenced by grain size and mangrove type. The results of this study will be useful in considering the type of mangrove planted as a study material in mitigation for mitigating global climate change.