Category: Ecology

Summary: Finding the juvenile-adult coupling where ecological modularity loses its stabilizing effect.

Ecological modularity can promote stability, but real populations are also divided into life stages that interact differently. This experiment asks when coupling between juvenile and adult components becomes strong enough to erase the stability advantage of modular community structure.

The script builds dense random Jacobians with juvenile-adult blocks and modular interaction structure, then bisects the stage-coupling parameter while increasing species count. Stability is tracked through the leading eigenvalues of the full stage-structured system, not just a coarse community-level summary.

The result connects two active ideas in theoretical ecology: modular organization and population structure. It tests whether a mechanism that stabilizes unstructured communities still works once life-history detail is added explicitly.

Method: Dense non-symmetric eigensolve with iterative deepening and bisection on juvenile-adult coupling in stage-structured ecological Jacobians.

What is measured: Critical stage-coupling threshold, leading-eigenvalue stability boundary, system size reached, and bracket width.