Natural capital.

Natural capital is the total ecological system and all its entities that are not human-made and exist naturally in the world. Examples are rocks, minerals, plants, animals, soil, trees, and water. More specifically, these can be categorized asnonrenewable natural resources, such as oil and minerals, and renewable resources, such as fish, water, and timber. The work of ecosystems must be balanced and maintained in order to continually provide capital. This can happen within a natural system or as a response to human intervention, such as pollination and flood control.