Category: Ecology

Summary: Testing whether intermediate reserve-duty cycles outperform both always-open and mostly-closed extremes when delayed management interacts with Allee effects, seasonality, and patch heterogeneity.

Populations with Allee effects can collapse when they are pushed below a critical density, yet fully closing or fully opening a reserve is not always the best way to avoid that outcome. This experiment asks whether delayed feedback in reserve management creates a re-entrant window where intermediate closure schedules protect biomass better than either extreme.

The model simulates two coupled biomass patches with logistic growth, Allee thresholds, dispersal, harvest pressure, seasonal forcing, and delayed adjustment of management effort. It then compares several reserve-duty fractions and records whether middle values produce higher long-run biomass, fewer low-biomass episodes, and less extinction risk than the edge cases.

That makes the result a policy-timing and nonlinear-ecology question at once. Rather than assuming that more protection is always better, the experiment looks for a nonmonotone response produced by the interaction of delayed control, patch differences, and threshold-like population dynamics.

Method: Repeated two-patch biomass simulations with Allee effects, seasonal forcing, delayed effort updates, and sweeps over reserve-duty fractions.

What is measured: Reentrant gain of intermediate reserve duty, extinction improvement, reduction in low-biomass occupancy, support rate across trials, and biomass statistics for edge versus middle reserve schedules.