A Unified Instrument Framework for Detecting, Scaling, and Stress-Testing Hydrological–Biological Impedance Collapse Across Dryland and Rainforest Systems

This preprint introduces an instrument-grade governance framework for detecting, classifying, and stress-testing regime shifts in land–water systems across dryland and rainforest environments. The framework unifies desertification and deforestation dynamics under a single structural definition of impedance collapse: A system undergoes impedance collapse when biological structures mediating the dominant moisture-retention mechanism at the active coupling layer are degraded beyond biological substitution capacity, resulting in a persistent shift to a lower-retention regime maintained by positive feedback at the system’s characteristic feedback reach. The architecture includes: • Regime classification using aridity index as a gradient indicator of coupling-layer dominance (pedological vs atmospheric) • A dryland instrument loop using runoff coefficient (RC) and sediment transport continuity to detect partitioning and connectivity shifts • A rainforest instrument loop using runoff ratio (RR) as the primary metric with canopy throughfall deficit (CTD) as corroborator and a BACI load test • Explicit scaling logic from plot partitioning to landscape connectivity • Functional retirement criteria verified by load testing • Envelope limits distinguishing hard constraints (under the current intervention class) from soft, recoverable constraints • A dimensionless resilience depth metric (RD = 1 / (Δ_norm · T_norm)) based on normalized perturbation response and recovery time All thresholds are treated as gradient indicators rather than fixed physical constants. The framework is fully falsifiable, baseline-disciplined, and portable across systems without asserting biome symmetry or universal parameter equivalence. This paper is methodological. It does not make climate attribution claims, restoration guarantees, or biome equivalence assertions. Its contribution is a structured measurement architecture for governance, field diagnostics, and comparative resilience analysis. KEYWORDS Impedance collapse Regime shift Desertification Deforestation Hydrological connectivity Evapotranspiration recycling Runoff coefficient Runoff ratio BACI design Resilience depth Hysteresis Land system governance