Both internal and external stakeholders of organisations are increasingly aware of the importance of natural capital in creating sustainable value. Corporate reporting on natural capital has been growing considerably over the past couple of decades, particularly for issues such as climate change, water and waste. Yet, quantified data disclosed is currently essentially limited to annual flows, such as resource use or emissions, failing to account for net impact on natural capital. This paper proposes new conventions to double-entry bookkeeping to facilitate net biodiversity impact accounting and disclosure. Case study applications involve assessing the net ecosystem impacts of both the Nimes-Manduel-Redessan train station and Cossure offset projects, in the South of France, to record the periodic and accumulated changes in ecosystem extent and condition, without compromising the incommensurability of biodiversity components. Assuming the two projects belong to the same business, the scaling up of project-level data and their aggregation at the company level are demonstrated through the development of Statements of Biodiversity Performance and Position.
