FA-65762 / Ecological population dynamics / Member archive
MacArthur-Wilson island equilibrium: equilibrium richness · case 02
Predicted richness can exceed the mainland pool.
Case contract
I0 = imax*exp(-distance/d0); E0 = emax*a0/area; S* = I0*P/(I0+E0); turnover = I0*E0/(I0+E0); return [S*, turnover, I0, E0] rounded 4; None for non-positive parameters or negative distance.
Why this case matters
Population projections set harvest quotas, conservation status and pest-control timing; a wrong update order, boundary or rate conversion silently changes management advice.
One recorded failure
Sample boundary fixtureThis sample comes from the broken implementation of a controlled reproducer.
| Boundary fixture | Actual | Expected | Outcome |
|---|---|---|---|
| regression: near large island | [4093.6538, 0.1907, 4.0937, 0.2] | [190.6839, 0.1907, 4.0937, 0.2] | Failed |
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