A more thorough explanation:

Term: ex natura
Definition: Ex natura means "according to nature." It is a Latin term used to describe something that is natural and not artificial or man-made.
Examples: A forest is an example of something that is ex natura because it is a natural environment that has not been created by humans. Another example is a river, which flows naturally and is not controlled or manipulated by humans.
Explanation: The examples illustrate the definition of ex natura because they are both natural environments that exist without human intervention. They are not artificial or man-made, but rather are part of the natural world. The term ex natura is used to describe things that are natural and not created by humans, and these examples demonstrate that concept.