Some determinants of the spatio-temporal fire cycle in a mediterranean landscape (Corsica, France)

Based on recent needs to accurately understand fire regimes and post- fire vegetation resilience at a supra- level for carbon cycle studies, this article focusses on the coupled history of fire and vegetation pattern for 40 years on a fire- prone area in central Corsica ( France ). This area has been submitted since the beginning of the 20th century to land abandonment and the remaining land management has been largely controlled by frequent fires. Our objectives were to rebuild vegetation and fire maps in order to determine the factors which have driven the spatial and temporal distribution of fires on the area, what were the feed backs on the vegetation dynamics, and the long- term consequences of this inter- relationship. The results show a stable but high frequency of small fires, coupled with forest expansion over the study period. The results particularly illustrate the spatial distribution of fires according to topography and vegetation, leading to a strong contrast between areas never burnt and areas which have been burnt up to 7 times. Fires, when occuring, affect on average 9 to 12% of the S, SE and SW facing slopes ( compared to only 2 to 5% for the N facing slopes ), spread recurrently over ridge tops, affect all the vegetation types but reburn preferentially shrublands and grasslands. As these fire- proning parameters have also been shown to decrease the regeneration capacity of forests, this study highlights the needs in spatial studies ( both in terms of fire spread and vegetation dynamic ) to accurately apprehend vegetation dynamic and functionning in fire- prone areas.