Conceptual models of ecosystem services impact causality were reviewed. Most are used in Integrated Assessments of marine environments, but do not consider reasonably foreseeable future developments.
The determination of impact causality is a cornerstone of cumulative impact assessment. A literature search on conceptual models of causality of cumulative impacts (CIs) on ecosystem services yielded 91 papers published in the period 2000-26. We found 25 variants of models, most of which are built upon the DPSIR approach (driving force-pressure-state-impact-response), while others are grounded on the ecosystem services cascade (action-structure-function-service-benefits-value). Most models do not systematically address cumulative impacts. When featured, CIs are represented by simple cause-effect or Sankey diagrams depicting multiple pressures on components. Additionally, the receptors of CIs are usually biotic groups, species, or habitats, with rare examples using ecosystem services. Most models captured in the review are based on the ecosystem-based management paradigm and used in Integrated Environmental Assessments of marine environments, mainly for quantitative risk assessments, by weighting different pressures and determining cumulative risks. It was observed that (i) models rarely distinguish accumulation processes, such as nibbling or time crowding, or between additive and synergistic impacts and (ii) pressures contributing to changing the state of valued components rarely include reasonably foreseeable future developments. Such gaps should be addressed by a new integrated proposal of a conceptual causality model. Although the existing models were not conceived to be applied at project, multi-project, or regional CIA, their rationale can be used as a promising base
Luis E Sánchez is Full Professor at the University of São Paulo. He authored several academic papers, textbooks and guidebooks on environmental and social impact assessment.