[img]2012q1/ct_etoefm_etoefspeakb_2095_20121[/img] The university library ha

Professor
    The flow of energy through life is not an endless cycle. The energy doesn’t go round and round getting used over and over again and never fading out. Its passage through the food chain can better be described as in and out. As energy moves up the food chain, there is less and less of it to go around.
    Most of the solar energy that falls on the earth is not used by plants. It bounces back to space or heats the air, oceans and ground, and makes the weather. So we should say the plants only get a little bit of the solar energy that hits the earth; and then the herbivores only get a portion of the energy that hits the plants; and still further on the carnivores and decomposers only get a fraction of the energy that was eaten by the herbivores. As a result, at the end of the chain there isn’t much of that original solar energy left. So we can see why we need sunshine everyday and new plants must keep growing. Otherwise, the whole system would quickly run out of energy and everything alive would come to a "dead" stop.