Fractal size-distributions of wildfires in hierarchical landscapes: Natura facit saltus?

A number of recent papers have suggested that wildfire cumulative frequency-area distributions exibit a sequence of restricted power-law regions delimited by more or less abrupt cut-offs. However, upon closer inspection, most log-log cumulative size distribution plots of wildfires do not reveal strong evidence of sharp discontinuities in the scaling exponent. For instance, while approximately piecewise straight, the actual patterns show clear indication of upper convex curvature. It seems therefore that instead of the traditional succession of restricted power-law regions, with each one being characterized by a close-to-constant scaling exponent, most 'non-ideal' natural fractals or 'semifractals' can be explained by a continuous fractal dimensional transition in which the scaling exponent continuously changes with scale. This article suggests that wildfire time series are semifractal objects and discusses the consequences of this observation within the context of ecological hierarchy theory