Conceptual model of wildfire cycle in response to increasing fire frequency, in a semiarid Mediterranean shrubland ecosystem:
Following a fire event, inflammability gradually increases as biomass, dead plant mass and litter accumulate; eventually, a senescence stage is reached when a new wildfire is likely to occur. Fire-related ash deposition and mineralization result in high nutrient availability in the soil, facilitating rapid recovery of vegetation and increase in inflammability, eventually resulting in another fire event and re-initiation of the cycle. However, if fire frequency is abnormally high the ecosystem nutrient capital does not fully recover, finally leading to long-term soil fertility depletion, slower post-fire vegetation recovery, increased erosion, and desertification.