Forest-fire model with resistant trees

The role of forest heterogeneity in the long-term, large-scale dynamics of forest fires is investigated by means of a cellular automata model and mean-field approximation. Heterogeneity was conceived as trees (or acres of forest) with distinct strengths of resistance to burning. The scaling analysis of fire-size and fire-lifetime frequency distributions in the non-interacting fire steady-state limit indicates the breakdown of power-law behavior whenever the resistance strength parameter R exceeds a certain value. For higher resistance strength, exponential behavior characterizes the frequency distributions, while power-law like behavior was observed for the lower resistance case in the same manner as reported in the literature for a homogeneous counterpart model. For the intermediate resistance strength, however, it may be described either by a stretched exponential or by a power-law plot whenever the fraction of recovering empty cells by susceptible trees does not exceed or exceeds a certain threshold, respectively, also suggesting a dynamical percolation transition with respect to the stationary forest density