Abstract
•SOC concentrations were adversely affected by the increase in total P and total N.•SBD was positively affected by higher EC and TDS.•Density of A. marina was positively correlated with total N and total P.•Anthropogenic factors played a significant role in the SOC pool value.
In the present work, we assessed the carbon sequestration capacity of mangrove forests (Avicennia marina) in relation to nutrient availability and salinity gradients along the Red Sea coast of Saudi Arabia. This was achieved through estimating the sediment bulk density (SBD), sediment organic carbon (SOC) concentration, SOC density, SOC pool, carbon sequestration rate (CSR) and carbon sequestration potential (CSP). The present study was conducted at 3 locations (northern, middle and southern), using 7 sites and 21 stands of mangrove forests (A. marina) along ∼1134km of the Red Sea coastline of Saudi Arabia (from Duba in the north to Jazan in the south), all of which are in an arid climate. The correlation coefficients between the water characteristics and the first two Canonical Correspondence Analysis (CCA) axes indicated that the separation of the sediment parameters along the first axis were positively influenced by TDS (total dissolved solids) and EC (electric conductivity) and were negatively influenced by total N and total P. On the other hand, the second axis was negatively correlated with total N, total P, EC and TDS. The SOC pools at the northern (10.5kgCm−2) and southern locations (10.4kgCm−2) were significantly higher than the SOC pool at the middle location (6.7kgCm−2). In addition, the average CSR of the northern (5.9gCm−2yr−1) and southern locations (6.0gCm−2yr−1) were significantly higher than they were in the middle location (5.0gCm−2yr−1).