From invasive species to circular resources: a global synthesis of biomass utilisation pathways and life cycle environmental performance

Invasive alien species (IAS) are among the leading global drivers of biodiversity loss and ecosystem disruption. At the same time, the large volumes of biomass generated during their control represent a potential resource that could be integrated into circular economy strategies if appropriately managed and valorised. Despite growing interest in this topic, existing research remains fragmented, often focusing on single species or isolated applications, with limited integration of environmental performance across the life cycle. This study provides a comprehensive and integrated synthesis of the current scientific evidence on IAS biomass utilisation, aiming to identify the most studied species, their main valorisation pathways, their energetic and agricultural potential, and the environmental impacts associated with derived products using life cycle assessment (LCA). A systematic review of 170 studies published between 1985 and 2024 was conducted, classifying biomass uses into seven categories and analysing key physicochemical and energetic indicators. In addition, environmental sustainability was assessed through a focused review of 13 LCA studies on products derived from Arundo donax, Pinus pinaster and Eucalyptus globulus, complemented by an in-depth analysis of six LCA studies specifically addressing the genus Acacia. The results indicate that energy production and agricultural applications are the most frequently investigated valorisation pathways, accounting for 36% and 24% of the analysed literature, respectively, with calorific value being the most commonly used indicator of energy potential. Agricultural products such as compost and biochar generally exhibit physicochemical properties suitable for soil amendment, although substantial variability exists among species and processing routes. LCA evidence further reveals that environmental impacts are driven primarily by technological choices rather than by species identity alone. Energy-intensive or chemically complex processes are associated with higher environmental burdens, whereas low-transformation pathways show more favourable environmental profiles. In the case of Acacia, pellet production consistently emerges as the option with the lowest environmental impact. Overall, the findings demonstrate that IAS biomass valorisation is not inherently sustainable and that careful selection and optimisation of processing routes are essential to minimise environmental trade-offs. By integrating biomass properties, utilisation pathways and life cycle environmental performance, this study provides robust evidence to support sustainable invasive species management and cleaner production strategies within a circular bioeconomy framework.