• Biotic and Abiotic Cycles Key Concepts

    SchoolCenter Picture

    • In order to understand how an ecosystem functions, one must understand the concept of a system and be able to envision models of systems.

    • To analyze the interactions resulting in a flow of energy and matter throughout the ecosystem, one must identify the elements of the system and interpret how energy and matter are used by each organism.

    • Many important elements and compounds cycle through the living and nonliving components of the environment as a chain of events that continuously repeats.

    • Energy enters an ecosystem through the process of photosynthesis and is p assed through the system as one organism eats and is, in turn, eaten.

    This energy flow can be modeled through relationships expressed in food webs.

    • Materials are recycled and made available through the action of decomposers.

    • The amount of energy available to each successive trophic level (producer, first-order consumer, second-order consumer, third-order consumer) decreases. T his can be modeled through an energy pyramid , in which the producers provide the broad base that supports the other interactions in the system.