Severe wildfires, which occur frequently in Mediterranean regions, could affect the ecosystem service of carbon sequestration in the plant-soil system for a period of time that may vary depending on the considered ecosystem. In the framework of PRIN 2022 “FIRE LEGACIES AND RESILIENCE OF SOIL AND PLANT COMMUNITIES IN MEDITERRANEAN COASTAL FORESTS (FLER_MeCoFor)” (20222CT8J3), the effect of wildfires on organic carbon stock in trees and soil was assessed in a Southern Italy coastal pine forest of EU conservation interest (SAC IT9130006) historically prone to wildfires over a time span ranging from 4 to 42 years.

The carbon stock in the standing above-ground tree biomass (CT) and soil organic carbon stock (SOC) in organic layer (O-layer) and mineral soil (0-5 cm and 5-10 cm S-layers) were analysed in seven stands differing for the time elapsed since fire (4, 7, 12, 30, 32, 38, and 42 years), in each of them the burned plot was compared with unburned control plot. No standing trees were detected in plots burned from 4 up to 12 years; by contrast, trees were found in plots burned from 30 up to 42 years, but the CT stock was generally significantly lower than in control up to 42 years after the fire. Compared with the control, a significant reduction in SOC was observed in O-layer and S-layer (0-5 cm) of the plots burned from 4 to 7 years. The SOC of O-layer was still generally significantly reduced from 12 to 42 years after the fire, whilst the SOC of the S-layers showed no significant differences between burned and control plots during the same period. The data show a long-term decline in the C sequestration ecosystem service within standing above-ground tree biomass and soil, suggesting a low resilience of this service to wildfires in the studied ecosystem.