Model
The world is a grid of patches — forest, cleared land, habitat — and a population of animal agents that move, feed, reproduce and die according to what their patch and the climate allow. Deforestation removes forest patches at a configurable rate; climate variables shift temperature and rainfall, which change patch productivity. Animals respond by migrating toward remaining habitat, and population plots show the lag between habitat loss and population collapse.
What it shows
Emergence: no rule says “populations crash when forest falls below a threshold”, yet that is what the runs produce, and the threshold moves with the resilience slider. It was a first exercise in translating a real system into agents and rules and watching what the rules imply.