Short term and long term studies are used to determine the effects of environmental changes (natural and man-made) on the health of the organisms within that environment.
The natural world is defined by organisms and life processes which conform to principles regarding conservation and transformation of matter and energy. Living organisms use matter and energy to build their structures and conduct their life processes, have mechanisms and behaviors to regulate their internal environments and to respond to changes in their surroundings. Knowledge about life processes can be applied to improving human health and well being.
The life processes of organisms are affected by their interactions with each other and their environment, and may be altered by human manipulation.