Persistence Geometry in Ecological Regime Shifts A Resilience-Model Extension Distinguishing Boundary Proximity from Structural Trajectory

Current ecological early warning signal (EWS) frameworks primarily estimate boundary proximity through indicators such as rising variance and lag-1 autocorrelation. However, systems exhibiting similar proximity signatures can still undergo substantially different transition dynamics.

This study introduces a constrained resilience-model extension distinguishing boundary proximity from structural trajectory. Boundary proximity is treated as a measure of how close a system resides to a bifurcation threshold, while trajectory variables represent the system’s structural capacity to absorb stress and resist continued movement toward that boundary.

The framework operationalizes trajectory through two primary dimensions:
(1) functional redundancy across stabilizing ecological guilds, and
(2) relative repair/degradation dynamics under sustained environmental pressure.

A fully pre-registered, zero-trust computational architecture was constructed prior to empirical deployment. The pipeline includes:
- dynamic Environmental Data Initiative (EDI) manifest auditing,
- automated morphological exclusion filtering,
- functional guild translation layers to prevent taxonomic drift,
- retrospective baseline normalization,
- and locked equal-weight geometric assembly.

The framework was deployed against North Temperate Lakes (NTL) Long-Term Ecological Research datasets using stratified Cox proportional hazards competition between:
(1) proximity-only models and
(2) composite proximity-plus-trajectory models.

Initial Phase 1 deployment produced an intentionally conservative indeterminate outcome due to limited event geometry within a single matched lake pair. However, the analysis demonstrated measurable divergence between noisy proximity behavior and smooth structural trajectory erosion preceding eutrophication transition.

The study establishes a reproducible empirical architecture for testing whether trajectory variables carry predictive weight beyond proximity metrics alone in ecological regime shifts.

Future phases will scale the analysis across additional shallow-lake transition histories in North American and European ecological repositories under fully locked methodological constraints.