Fire resilience and forest restoration in Mediterranean fire-prone areas

Abstract

Mediterranean ecosystems are of importance worldwide because they are biodiversity hot spots. In these areas, forest fires have been modelling the landscape since the Pleistocene Era. Consequently, plant communities inhabiting this fire-prone area have developed adaptive traits (e.g. serotiny) or life-history strategies to persist, exhibiting a high degree of survival or recovering after frequent fires or other disturbances, such as severe drought. In general, this implies high resilience, but in recent years aridity and fire dynamics have been increasing due to global climate change, which has strongly affected the Mediterranean Basin. These changes are inducing higher risks of soil loss and lower plant productivity in the long term, which influences the resilience of the community present before the disturbance. Some species are pirophytes (fire adapted), such as Cistus sp. (Ferrandis et al., 1999a), or pirophyles (fire dependant). Pinus halepensis Mill. and some populations of Pinus pinaster Aiton have been catalogued as pirophylous species. They are not promoted by fire (Martínez-Sánchez et al., 1996) but show colonizer behavior in the absence of fire (Ayari et al., 2011). The main four components of resilience are elasticity (recovery rate), amplitude (fire severity inducing no recovery), malleability (differences from the previous state) and damping (oscillation of ecosystem parameters). If the plant community does not recover after disturbance or natural characteristics do not achieve forest planning objectives, restoration and stand improvement through forest management are important choices for lowering the aridity risk.