How to define and quantify substitution effects in the bioeconomy

Key message Research on substitution effects in the bioeconomy remains conceptually fragmented and methodologically narrow—focused predominantly on fossil-to-biomass material and energetic substitution, forest-derived biomass, carbon-related metrics, and single-method assessments. This limits its policy relevance. Comprehensive monitoring frameworks for sustainable biomass use must integrate environmental, behavioral, and systemic perspectives. Moving beyond a wood-based focus is essential to address socio-economic trade-offs and cross-border effects, thereby guiding robust, evidence-based policies. Context Substituting fossil-based resources with renewable biological alternatives is crucial for developing the bioeconomy. However, varied definitions and methods for quantifying substitution effects limit comparability and reduce policy relevance. Aims This scoping review examines how substitution effects are defined and assessed in the bioeconomy literature. It identifies methodological trends, research gaps, and implications for monitoring biomass use. Methods Following PRISMA-ScR guidelines, we analyzed 57 peer-reviewed articles from Web of Science and Scopus. The selected literature spans over twenty years and covers various types of biomass across diverse sectors. Results The predominant literature focuses on material and energetic substitution based on forest-derived biomass, primarily wood. Life Cycle Assessment (LCA) is the dominant methodology, with the displacement factor (DF) frequently used as the quantification metric. Research is concentrated in construction, energy, and other wood-based industries, often emphasizing CO2-related mitigation indicators. A recent shift toward research on material substitution reflects evolving policy and regulatory contexts. Conclusion While LCA remains dominant, robust interdisciplinary assessments require complementary approaches—such as behavioral economics and physical accounting—to fully capture substitution effects. Future monitoring frameworks should integrate critical dimensions, including biomass-to-biomass substitution, cross-border impacts, and land use trade-offs, to enhance evaluation accuracy. Moreover, expanding the analytical scope beyond purely environmental concerns will enable a more comprehensive assessment of substitution effects in the bioeconomy.