Dr. Liam Lysaght:

Biodiversity and biodiversity policy are very much evidence-based issues. Biodiversity quality is either being maintained and enhanced, or biodiversity is suffering loss. The only effective way to measure success or failure of biodiversity policy is against this trend. Biodiversity is measured by how well ecosystems function and how efficiently they deliver the ecosystem services that we all benefit from, such as pollination, nutrient cycling, soil fertility, water purification, etc.