Ecosystem is a system formed by the living creatures in a certain sphere and their closely related non biological surroundings. In the system, the material and the energy is constantly circulated between the creatures and between the creatures and the environment thus form a self-sustainable, relatively stable and independent integrated systemEcosystem is a system formed by the living creatures in a certain sphere and their closely related non￾biological surroundings. In the system, the material and the energy is constantly circulated between the creatures and between the creatures and the environment, thus form a self-sustainable, relatively stable and independent integrated system