Even a simple ecosystem is very, very complex. In order to work with nature's complexity, we can focus on the fundamental processes that operate in any ecosystem.
Four basic processes at work in all ecosystems allow us to quickly gauge the health of the land:
These processes are sometimes called the four ecosystem foundation blocks because they are so fundamental to ecosystem function.
Modifying any one of these processes automatically changes all of them because in reality, they are only different aspects of the same thing. Think of them as four different windows through which you can observe the same room. Or imagine them as the blood, breath, organs, and nerves in your body. You cannot have a healthy liver without air to breathe, or have healthy lungs if your liver fails!
In order to have an effective water or mineral cycle, or adequate energy flow, an ecosystem must have communities of living organisms. For living things to thrive, they need effective energy flow to feed them, a water cycle that supplies adequate moisture, and a mineral cycle that supplies vital nutrients. All four processes work together to create a healthy or unhealthy ecosystem.