Evaluasi Pertumbuhan Rhizophora apiculata pada Rehabilitasi Lahan dan Pendugaan Potensi Stok Karbon dan Fluks Karbon Dioksida pada Dua Jenis Hutan di Desa Perlis Langkat

Abstract

Mangrove forests are generally found along the coast in the tidal zone and are known to be the only woody halophytes. Mangrove forests are the most efficient and productive carbon sinks. As a result of the increasing rate of deforestation and degradation, mangroves produce substantial carbon emissions and contribute to most greenhouse gas (GHG) emissions. The objectives of this study were to determine the success rate of Rhizophora apiculata mangrove planting in October to December 2022, analyze the structure and composition of natural and restoration mangrove forests, and calculate the total carbon stock and carbon dioxide gas flux in natural and restoration mangrove forests. The planting method was carried out by inserting in the vacant part of the rehabilitation area, data collection of general forest structure variations was carried out by means of a non-destructive census by measuring the diameter, height, and species found as a whole, to calculate the value of carbon stocks using the allometric equation with DBH> 5cm in natural forests and restoration forests, CO2 gas flux data collection methods were measured using the static closed chamber method. The percentage of success rate of planting carried out is 67.5% of the total 200 seedlings planted. The species found in natural forests are Rhizophora apiculata, Rhizophora stylosa, Scyphiphora hydrophyllacea, and Sonneratia alba with a total of 134 individuals with tree levels found while in restoration forests are Rhizophora apiculata, Rhizophora stylosa, Scyphiphora hydrophyllacea, Sonneratia alba, Acacia leptocarpa, and Nypa fruticans with a total of 130 individuals with tree levels found. The total carbon stock value found in the natural forest was 10.75 mg/ha and the total carbon stock in the restoration forest was 6.51 mg/ha. Total soil carbon stocks in natural and restoration forests were 2,345 MgC/ha. The largest value of dead wood carbon was found in transect 2, which was 14.50 mg/ha in natural forest and 6.46 mg/ha in restoration forest. The highest average CO2 flux during the dry season was found in the natural forest at high tide of 1.000 mgCO2/m2/h and in the rainy season the highest average flux was found in the natural forest at high tide of 959 mgCO2/m2/h.