Subject:
Chapter 54 Ecosystems Lecture Outline Overview: Ecosystems, Energy, and Matter An ecosystem consists of all the organisms living in a community as well as all the abiotic factors with which they interact. The dynamics of an ecosystem involve two processes that cannot be fully described by population or community processes and phenomena: energy flow and chemical cycling. Energy enters most ecosystems in the form of sunlight. It is converted to chemical energy by autotrophs, passed to heterotrophs in the organic compounds of food, and dissipated as heat. Chemical elements are cycled among abiotic and biotic components of the ecosystem. Energy, unlike matter, cannot be recycled.
