Struktur Komunitas, Biomassa Permukaan dan Status Simpanan Karbon Biru di Kawasan Mangrove Terdegradasi Kabupaten Kolaka

Abstract

: Ekosistem mangrove memiliki potensi yang cukup besar dalam menyerap emisi karbon dari atmosfer. Karbon tersebut mampu tersimpan di dalam biomassa maupun sedimen, dan dikenal sebagai blue carbon. Meskipun demikian, degradasi mangrove dapat mengganggu potensi tersebut. Tujuan dari penelitian ini adalah untuk mengetahui struktur komunitas, biomassa permukaan (AGB), simpanan karbon biru vegetasi mangrove, serta kemampuan serapan karbon ekosistem mangrove yang telah mengalami degradasi di sepanjang pesisir Kabupaten Kolaka. Ekosistem mangrove di kawasan tersebut merupakan mangrove tepian (Fringe Mangrove), dan ketebalannya kurang dari 100 meter. Penelitian ini menggunakan metode transek kuadrat sejajar garis pantai. Sebanyak 5 plot berukuran 100m² diletakkan disepanjang transek. Data yang dikoleksi di setiap plot berupa diameter batang (dbh), jenis, dan jumlah jenis. AGB diestimasi menggunakan persamaan allometrik yang telah dikembangkan oleh beberapa peneliti terdahulu. Sementara itu stok karbon diestimasi menggunakan data AGB dan konstanta karbon dari bahan organik. Hasil penelitian menunjukkan bahwa ekosistem mangrove di pesisir Kolaka tersusun atas 8 spesies mangrove. Kerapatan mangrove tertinggi berturut-turut stasiun 3 (2180 ind/ha; kategori baik), stasiun 4 (2160 ind/ha; kategori baik), stasiun 1 (1520 ind/ha; kategori baik), dan stasiun 2 (1160 ind/ha; kategori sedang). Total AGB untuk seluruh stasiun sebesar 1242,29 ton/ha dengan AGB tertinggi pada stasiun 4 (455,58 ton/ha). Total stok karbon vegetasi mangrove untuk seluruh stasiun yaitu sebesar 583,85 ton/ha, dengan stok karbon tertinggi terdapat pada stasiun 4 (214,11 ton/ha). Sementara itu, total serapan karbon untuk seluruh stasiun sebesar 1362,46 ton/ha, dengan serapan karbon tertinggi terdapat pada stasiun 4 (499,65 ton/ha). Nilai AGB berbanding lurus dengan nilai stok karbon dan serapan karbon.

Mangrove ecosystem has a great potential to absorb carbon emission from atmosphere. Those carbon could be stored into the biomass as well as into the sediment, and it’s well known as blue carbon. Nevertheless, mangrove degradation could disturb those mangrove potential. The aims of this study were to knows the community structure, aboveground biomass (AGB), blue carbon stocks of mangrove vegetation, as well as the ability of carbon absorbtion of degraded mangrove ecosystem along Kolaka Coastal Line. The mangrove ecosystem at those areas was a fringe mangrove, and the mangrove thickness less than 100 meters. This study using quadratic transect method prependicular to the coastal line. 5 plots sized 100m² were placed along transect line. The data were collected in each plot were stem diameter (dbh), species and total of species. The AGB were estimated using allometric equation that has been developed by previous researcher. Meanwhile, the carbon stock was estimated by using the AGB data and carbon constant value from organic matter. The results of this study showed that mangrove ecosystem of Kolaka coastal line constructed by 8 mangrove species. The highest mangrove density were station 3 (2180 ind/ha; good category), station 4 (2160 ind/ha; good category), station 1 (1520 ind/ha; good category), and station 2 (1160 ind/ha; medium category) respectively. The AGB total for all stations was about 1242,29 ton/ha, with the highest AGB was in the station 4 (455,58 ton/ha). The total of carbon stock of mangrove vegetation for all stations was about 583,85 ton/ha, with the highest carbon stock was in the station 4 (214,11 ton/ha). Meanwhile, the total of carbon absorbtion for all stations was about 1362,46 ton/ha, with the highest carbon absorbtion was in the station 4 (499,65 ton/ha). The AGB values has directly proportional to the carbon stock and carbon absorbtion.