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.
Charles Carroll (Wed,) studied this question.