Estimasi Stok Karbon Tanah dan Biomassa Mangrove (Rhizophora apiculata) di Desa Pulau Sembilan, Kabupaten Langkat

Abstract

This study aims to examine the potential for carbon storage in the mangroves of Rhizophora apiculata, analyze the estimation of carbon stocks in soil and biomass with various calculation methods, and assess the relationship between soil carbon and mangrove biomass carbon. This research was carried out on the mangrove ecosystem in Pulau Sembilan Village, Langkat Regency, with soil sample analysis carried out at the Research and Technology Laboratory, Faculty of Agriculture, University of North Sumatra, Medan, from June to August 2025. This study used a Group Random Design with 2 treatment factors and 3 replicates. The first factor is the mangrove soil carbon calculation method which consists of 4 treatments, namely IPCC (2003) method (T1), SNI (2019) method (T2), Poeplau et al. (2017) (T3) method and Fenton et al. (2024) method (T4). The second factor is the mangrove biomass carbon calculation method which consists of 4 treatments, namely Komiyama method (2008) (B1), INCAS method (B2), Chave et al. (2005) method (B3) and Kauffman and Donato (2012) method (B4). The results showed that 10–15 year old Rhizophora apiculata has great potential in carbon storage, with higher soil carbon stocks compared to biomass. The estimation of mangrove carbon stocks shows differences between calculation methods, where alternative methods in T4B3 and T4B4 treatment provide results that are close to the T1B1 reference method. The Fenton and INCAS methods are recommended as a single alternative method, while the Chave and Kauffman and Donato methods can be used when combined with Fenton. The relationship between soil carbon stocks and biomass is relatively weak but statistically positive, meaning that an increase in soil carbon stocks tends to be followed by an increase in biomass carbon stocks.