The movements of matter within and between ecosystem.
ex: involves biological, geological, and chemical processes. To keep track of the movement of matter in biogeochemical cycles, we refer to components that contain matter, including air, water, and organisms as pools. Processes that move matter between pools are flows. All of Earth's living organisms are composed of chemical elements- mostly carbon, hydrogen, nitrogen, oxygen, and phosphorus. Organisms survive by constantly acquiring these elements, either from their environments or the organisms that they consume. The specific chemical forms elements take determine how they cycle within the biosphere.
