Material flow analysis of forest biomass in Portugal to support a circular bioeconomy
A comprehensive understanding of how resources are utilized is required to support a circular bioeconomy. This article presents the first systematic assessment of forest biomass flows and stocks in Portugal and analyzes circularity and resource efficiency through a comprehensive set of indicators, while providing recommendations for their use and improvement in different contexts. A Material Flow Analysis was developed for 2015, including paper, wood panels, furniture, carpentry, packaging, other woodwork, and energy (firewood, pellets, charcoal, electricity, heat), addressing uncertainty. Material flow analysis indicators (e.g., domestic material consumption) and circularity/resource efficiency indicators (cascade factor, material circularity indicator, recycled input, recovery rate) were assessed. In 2015, 49% of forest biomass was used for energy and 51% for material production. The wood sector in Portugal is heterogeneous regarding circularity. Paper and wood packaging were the most recycled products (highest material circularity indicator: 0.49 and recovery rate: 54%), while the panels sector used the most industrial residues (highest cascade factor: 3.78). The indicators analyzed provided a complementary assessment of circularity, giving both system wide (cascade factor) and sector- (cascade factor, recycled input rate, recovery rate) or product-based (material circularity indicator) views. Cascade factor permits an analysis of the whole system and of separate sectors, and an assessment of post-consumer and industrial residues, and both material and energy use. Material circularity indicator considers closed- and open-loop recycling of post-consumer residues, being complementary to the cascade factor. Indicators providing complementary perspectives are important to capture multiple types of resource use and valorization within the bioeconomy system.