The natural environment

The natural environment, commonly referred to simply as the environment, is a term that comprises all living and non-living things that occur naturally on earth or some part of it (e.g. the natural environment in the United States). This term includes a few key components:

Complete landscape units that function as natural systems without massive human intervention, including all plants, animals, rocks, etc. and natural phenomena that occur within their boundaries.
Universal natural resources and phenomena that lack clear-cut boundaries, such as air, water and climate.
Natural features which occur within areas heavily influenced by man (such as wild birds in urban gardens).