Quantitative Analysis of Soil Organic Carbon in the Arid Mangroves of Qurm Nature Reserve, Oman

Abstract

Mangroves are highly effective carbon sinks, particularly for sequestering soil organic carbon (SOC) and regulating atmospheric CO₂ levels, thereby playing a vital role in mitigating climate change. However, the carbon sequestration potential of mangroves in arid regions remains poorly understood. This study examines SOC stocks and soil physicochemical properties in Avicennia marina stands within the Ramsar site, the Qurm Nature Reserve (QNR), in Muscat, Oman. Soil samples were collected from three zones: seaward (S1), midstream (S2), and landward (S3), at three depth intervals (0–20, 20–40, and 40–60 cm). The analysis showed significant differences in pH, Calcium Carbonate (CaCO₃), and bulk density across the sampling sites (p < 0.05), whereas electrical conductivity (EC) and SOC remained stable and showed no significant differences. Soil physicochemical parameters were consistent across depths. The results indicate a high potential for carbon storage in the QNR mangroves; the estimated SOC was 136.25±18.51 Mg C ha-1 in QNR, with the highest value recorded at S3 at a depth of 40-60cm (487.50±31.20 Mg C ha-1). These results underscore QNR's potential as a carbon sink and provide baseline data for conservation and climate mitigation efforts in arid coastal ecosystems.