Fig. 1: Schematic representation of the sensitivity of ecosystem components to environmental change.

Ecosystem components at critical thresholds (spheres located at the bottom of a slope) are exposed to the same persistent environmental change (indicated by the red arrows). The sensitivity of the components to change is illustrated by the time required (response time) to shift from an initial to a resulting state. Response times can be independent and homogenous (A1) or heterogenous (A2) among coexisting components. Interconnections between components (a sphere pulling other components) can reduce the heterogeneity in response times among coexisting components (A3). Response times can be homogenous across latitude (B1), homogenous between coexisting components but heterogenous across latitudes (B2), or heterogenous between components and across latitudes (B3). Note that definitions for specific terms are provided in the general glossary (Supplementary information).