Vertical Stratification Of Soil Organic Carbon Under Different Vegetation Types In The Karavasta Lagoon (Albania)

Vegetated coastal wetlands are considered a nature-based climate mitigation solution, since they can capture and store organic carbon for centuries to millennia. It is necessary to quantify the amount of stored organic carbon to calculate their sequestration capacity and include them in the context of international climate agreements. In this study, the distribution of organic carbon in the soils of Karavasta Lagoon was determined. The carbon stock of different vegetation types was compared while taking into account abiotic environmental variables that could influence their storage potential. Twenty-six points were sampled, up to a depth of 20 cm, dividing them into depth intervals of 0−5 −cm, 5−10 cm and 10−20 cm and measuring pH, EC, carbonates, and LOI for each depth. Total organic carbon (TOC) content was calculated by applying a conversion factor of 0.71 (TOC = 0.71 × LOI). Furthermore, different types of vegetation were mapped to overlap them with the chemical-physical characteristics of the sampling points. The results indicate that organic carbon concentrations are relatively uniform across vegetation types: halophytic vegetation, wooded dunes with Pinus species, and abandoned agricultural land. They show a clear decrease with depth, from 33.35 g/kg in the surface layer to 15.78 g/kg at 20 cm. On average, the sampled soils have a SOC density of 0.03 g cm-3 and a SOC stock of 55.02 ± 20.55 Mg C ha-1 within the top 20 cm, highlighting the role of the Karavasta Lagoon as an important blue carbon system in the context of climate change mitigation.