Simpanan Karbon dan Fluks CO2 Sebagai Indikator Keberhasilan Rehabilitasi Hutan Mangrove di Desa Lubuk Kertang Kabupaten Langkat Sumatera Utara

Abstract

Mangrove ecosystems provide valuable goods and services to coastal communities as a source of livelihoods, shoreline stabilization, and climate change mitigation. The 56% decline in mangroves due to illegal logging has triggered rehabilitation efforts conducted by the Center for Mangrove Science and Technology (PUIMangrove) of the University of North Sumatra since 2015 and 2016. This study aims to analyze vegetation dynamics, calculate carbon storage, and measure CO₂ fluxes during the rainy and dry seasons after 10 years of rehabilitation. Data were collected using a census method in the form of diameter at breast height (DBH) and tree height. As a result, 13 types of mangrove plants were found, consisting of 11 true mangroves (Aegiceras corniculatum, Avicennia marina, Bruguiera gymnorrhiza, Ceriops tagal, Excoecaria agallocha, Nypa fruticans, Rhizophora apiculata, Rhizophora mucronata, Rhizophora stylosa, Scyphiphora hydrophyllacea, and Sonneratia alba) and 2 types of associated mangroves (Acrostichum aureum and Finlaysonia maritima). Total carbon storage reached 123.44 MgC ha-¹, with an economic value of approximately IDR 558,581,137 ha⁻¹ using a carbon credit price of 19 USD per ton C and an exchange rate of IDR 16,711.50 per USD on November 6, 2025. The average CO₂ flux was recorded at 405.30±226.28 mg/m²/hour in the dry season and 379.12±258.12 mg/m²/hour in the rainy season. These findings indicate that mangrove rehabilitation in abandoned ponds effectively restores vegetation structure, increases carbon storage, and contributes to climate change mitigation as well as opens up opportunities for utilizing carbon-based environmental service schemes