Population dynamics with logistic growth, Allee effects, and harvesting. Click the phase portrait to set initial conditions. Multiple trajectories reveal stable/unstable equilibria.
Logistic: dN/dt = rN(1-N/K). With Allee effect: dN/dt = rN(N/A-1)(1-N/K) — creates an unstable equilibrium at N=A (Allee threshold). Below threshold: population collapses. Harvesting shifts stable equilibria and can cause tipping points. Relevant to fisheries management and conservation biology.