Two approaches for categorization can be contrasted.

On one hand, categorization can rely on scientific concepts issued from the internal dynamics of natural sciences, ecology. Variables, categories, used in the Madingley model can be considered as such an attempt.

On the other hand, categorization can be associated to concepts created by Conservation Sciences, the civil society, in particular environmental NGOs, rather documented by citizen sciences. Biodiversity indicators like species conservation status and red-list index, common bird index, flows and bundles of ecosystem services, are such categorizations.

These two categorizations differ in the way they consider the place of humans, their institutions, in ecological systems. While these are used in different models, scenarios, their combination should bring new knowledge, concepts. That might require deeper interactions with social sciences and humanities, integrating the logics of different institutions and representations.