Impacts of multiple stressors on biodiversity and ecosystem functioning: the role of species co‐tolerance

TLDR

Ecosystem resistance to a single stressor depends on tolerant species that compensate for sensitive competitors and sustain primary production. The study hypothesizes that resistance to multiple stressors depends on the sign and strength of species co‑tolerance, with positive correlations enhancing resilience. The authors propose that positive species co‑tolerance creates stress‑induced community tolerance, whereas negative co‑tolerance leads to stress‑induced community sensitivity, affecting ecosystem functioning.

Abstract

Ecosystem resistance to a single stressor relies on tolerant species that can compensate for sensitive competitors and maintain ecosystem processes, such as primary production. We hypothesize that resistance to additional stressors depends increasingly on species tolerances being positively correlated (i.e. positive species co‐tolerance). Initial exposure to a stressor combined with positive species co‐tolerance should reduce the impacts of other stressors, which we term stress‐induced community tolerance. In contrast, negative species co‐tolerance is expected to result in additional stressors having pronounced additive or synergistic impacts on biologically impoverished functional groups, which we term stress‐induced community sensitivity. Therefore, the sign and strength of the correlation between species sensitivities to multiple stressors must be considered when predicting the impacts of global change on ecosystem functioning as mediated by changes in biodiversity.