Lesson 3

Energy in an Ecosystem All the energy that consumers get comes from producers, directly or indirectly – The ultimate source of energy in nearly all cases is the sun A food chain shows the path of energy flow in an ecosystem.

An energy pyramid shows the amount of energy available to organisms at each level in the feeding order – 1 st level =energy is trapped and contained in producers – Other levels show energy available to consumers further up the food chain At each level, some energy is used to carry out life processes and some is lost (as heat). – Each level has only about one-tenth as much energy as the level below it Energy in an Ecosystem

A food web is a diagram of the feeding relationships among organism in a community. – Links together the different food chains in a community – Can be very complex, but illustrate how the different organisms in the web are interdependent Energy in an Ecosystem