We introduce an inverse-cascade model to explain self-organized critical behavior. This model is motivated by the forest-fire model. In the forest-fire model trees are randomly planted on a grid, sparks are also dropped on the grid resulting in fires in which trees are lost. In the...

A 2D distribution of microphytobenthic biomass is determined from a superficial sediment sampling on an exposed sandy shore. The distribution undergoes a very structured pattern, displaying a few dense patches over a wide range of low density patches. We perform a statistical analysis of this 2D...

The scaling properties of waves of topplings of the sandpile model on a fractal lattice are investigated. The exponent describing the asymptotics of the distribution of last waves in an avalanche is found. Predictions for scaling exponents in the forward and backward conditional probabilities...