Sánchez, LE, Margarido, NT, Souza, LR, Vieira, DG, Matos, CB, Kakinami, SH, Rosa, JCS & Morrison-Saunders, A 2025, 'Delivering biodiversity and nature positive outcomes through mine closure: theoretical perspectives and challenges of practice', in S Knutsson, AB Fourie & M Tibbett (eds), Mine Closure 2025: Proceedings of the 18th International Conference on Mine Closure, Australian Centre for Geomechanics, Perth, pp. 1-11, https://doi.org/10.36487/ACG_repo/2515_102 (https://papers.acg.uwa.edu.au/p/2515_102_Sanchez/) Abstract: Mining companies are increasingly committing to no net loss of biodiversity and nature positive outcomes consistent with recent international policies. Action is needed throughout the mining lifecycle, to ensure that gains will outlast closure by the company or possible divestment. Mine closure plans should thus specifically address biodiversity and nature outcomes. However, metrics for losses and gains accounting are site-specific and, despite sustained efforts, no consensus exists about parameters that could be universally applicable. To demonstrate actual outcomes, data collection and curation should be structured on the basis of five pillars. A robust biodiversity baseline, which is a usual requirement of environmental impact assessment, that can be used not only for regulatory approval purposes but could be strengthened as a reference for evaluating performance throughout the mine lifecycle. Impacts should be unambiguously identified and described in the environmental impact assessment to allow for accurate monitoring. Generic impact descriptions hinder interpretation of monitoring data. Monitoring should be designed to detect actual impacts and to document impact pathways including restoration goal attainment. Accounting for both direct and indirect impacts of mine development is necessary, especially when mining drives land use change, because direct footprint disturbance may be only a fraction of total mining disturbance. Outcomes of restoration and compensation measures, including biodiversity offsetting, should be rigorously evaluated against agreed-upon completion criteria over long time periods. We discuss the practical challenges of disclosing related information by reviewing sustainability reports of bauxite mining in the Brazilian Amazon. To effectively deliver nature positive commitments, mining companies need to follow-up the trajectory of biodiversity losses and gains throughout a mine lifecycle, and to factor them in their mine closure strategies. To enhance the role of closure planning to deliver biodiversity and nature positive outcomes, we call for further evolution of mine closure guidance to explicitly include nature positive goals. Keywords: bauxite, ecological restoration, impact monitoring, mine rehabilitation, no net loss, sustainability reporting