Multifunctionality assessments - More than assessing multiple ecosystem functions and services? A quantitative literature review

The capacity of a landscape or ecosystem to provide multiple socio-economic and ecological benefits to society is referred to as multifunctionality. While this topic is receiving growing attention in politics and research, the concept continues to lack implementation partly due to varying conceptualizations and assessments of multifunctionality. To analyze how multifunctionality is conceptualized, characterized and quantified in scientific publications, we reviewed 101 studies that used quantitative methods to assess landscape or ecosystem multifunctionality. On average, 7.9 +/- 4.7 ecosystem functions and services were considered, covering Provisioning (19%), Regulating (30%), Cultural (16%) and Supporting (35%) service categories. The studies ranged from micro-scale experiments to global analyses. Different methods were used to aggregate multifunctionality into a single metric (e.g. the number of ecosystem functions and services above a certain threshold, the average value of ecosystem functions and services, the sum of ecosystem functions and services). The interpretation of multifunctionality and the way it is operationalized varied largely among the studies: 42 studies assessed ecological and socio-economic variables in equal shares and often integrated stakeholders (33%). 59 studies focused on ecological variables only and did not include stakeholders except for one study (1.7%). Based on these findings, we discuss the implications of the conceptual and methodological ambiguity within multifunctionality assessments. We present the strengths and limitations of current approaches and provide recommendations for future multifunctionality assessments.