Ecosystem Terrarium: Closed-Loop Population & Water Cycle (2D)

This 2D companion replaces the 3D version's decorative orbiting fireflies with the ecology and biophysics a sealed terrarium actually runs on: Monod-limited plant growth competing for light, soil moisture and nutrients; a Holling type-II grazing loop between the plants and a herbivore population; a decomposer litter pool that recycles dead biomass back into the soil; and a closed evaporation/condensation water cycle across the glass, all six state variables RK4-integrated together and driven by six live sliders for light, day length, herbivore seeding, grazing rate, decomposition rate and starting soil moisture.