Forest Succession

Ecological succession describes directional change in species composition after disturbance. Each stage modifies the environment — pioneer grasses stabilize soil, shrubs create shade that benefits shade-tolerant trees, and mature forest suppresses pioneers. The model uses probabilistic cellular automaton rules based on shade tolerance: transitions depend on neighbor states. Disturbances (fire, windthrow) reset patches to bare ground, creating the mosaic of successional stages typical of real forests. The climax state is not static but dynamic equilibrium.