Soil is an important component of natural capital that provides many ecosystem services, such as habitat supply for a myriad of species, nutrient cycling regulation, and climate regulation through organic carbon sequestration. The soil organic carbon pool can be affected by anthropogenic disturbances, such as wildfires, which occur annually in large areas of Southern European countries.

This study aims to assess the effect of wildfires on soil organic carbon (C) in a coastal pine forest in Southern Italy included in the Special Area of Conservation (SAC) of the Natura 2000 Network (IT9130006 - Pinewoods of the Ionian Arch), as part of the PRIN 2022 FLER_MeCoFor Project. Wildfires that occurred in the study area were mapped using Landsat imagery in the Google Earth Engine platform. Fire effects were assessed in relation to the time since the last fire (4-42 years) through synchronic sampling carried out in 2024 at seven sites, each of which included burned plots and unburned control plots. In each plot, the weight and organic C content of the organic layer (O-layer, including both litter and fermentation layer) as well as organic C content and bulk density of the underlying mineral sandy soil (S layers, 0-5 cm, 5-10 cm) were measured.

In the most recently burned plots (in 2020, 2017 and 2012), fires caused a significant reduction in the weight of the O-layer and in the organic C content of the O-layer and S-layers, compared to controls. The differences between burned and control plots were less marked at sites affected by older fires (in 1994, 1992, 1986 and 1982). The data suggest that full recovery of the organic C pool after fire requires several years. Therefore, strategies need to be adopted to reduce the frequency and intensity of fires in areas prone to recurrent fires.