Spatial scale invariance of southern Australian forest fires mirrors the scaling behaviour of fire-driving weather events
Power law frequency-size distributions offorest fires have been observed in a range of environments.The scaling behaviour of fires, and moregenerally of landscape patterns related to recurringdisturbance and recovery, have previously beenexplained in the frameworks of self-organized criticality(SOC) and highly optimized tolerance (HOT). Inthese frameworks the scaling behaviour of the fires isthe global structure that either emerges spontaneouslyfrom locally operating processes (SOC) or is theproduct of a tuning process aimed at optimizing thetrade-offs between system yield and tolerance to risks(HOT). Here, we argue that the dominant role of selforganizedor optimised fuel patterns in constrainingunplanned-fire sizes, implicit in the SOC and HOTframeworks, fails to recognise the strong exogenouscontrols of fire spread (i.e. by weather, terrain, andsuppression) observed in many fire-prone landscapes.Using data from southern Australia we demonstratethat forest fire areas and the magnitudes of correspondingweather events have distributions with closelymatching scaling exponents. We conclude that thespatial scale invariance of forest fires may also be amapping of the meteorological forcing pattern.