Relationship between organic carbon and sediment properties in mangrove forests of three Bushehr coastal areas

Abstract

One of the main ecosystem services of mangroves is enhancing carbon sequestration, most of which is done by sediments. Therefore, recognizing sediment properties is useful to evaluate the factors affecting carbon uptake in mangrove sediments. To identify the relationship between sediment organic carbon (SOC) content and sediment properties, sampling from three mangrove forests in Bushehr (Iran) coastal regions (Asalouyeh, Basatin, and Malegonzeh) was performed at 6 different stations, and the SOC of the samples were measured by Walkley and Black method. The particle diameters were performed by the sieving and hydrometer method and the results were analyzed (Gradistat. v8). The results showed that the highest percent of particles were silt, ranging from 93.6 to 96.6%. Several sediment grain size properties were correlated with SOC. Two factors were analyzed in principal component analyses, which were responsible for 75.8% of the samples attrinbutes. Factor 1 was organic carbon (SOC), skewness, sand, mean size, sediment density, clay, and silt summation (clay & silt). Factor 2 included clay, sorting, and kurtosis. Organic carbon was positively correlated to sorting, clay & silt percent, and grain size (ɸ). Meanwhile, the SOC was negatively correlated to sediment density, C, sand percent, and skewness. Generally, by decreasing the size of the sediment particles, the amount of SOC increased. Areas with fine-grained sediments appear to be able to absorb more organic carbon.