Just as a doctor checks your body's basic function, biologists check the basic functions of an ecosytem. Researchers want to understand the larger ecosystem processes such as the flow of nutrients, biodiversity, and the natural cycles of water and minerals. They want to know the patterns of natural landscapes , map them, and compare these maps every so often to see how they change and why.
Researchers monitor wildlife and vegetation communities to look for change in their populations.
Certain focal species such as elk, spotted owls, and rare plants are selected and studied for their meaning to the ecosystem and the public. Compare and contrast.