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Energy Flow Through Ecosystems Chapter 5 section 1. OBJECTIVES:. OUR objectives: - Examine and characterize energy transfer in food webs and chains. - Determine the ULTIMATE source of energy. - Examine feeding relationships at work in ecosystems.
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OBJECTIVES: OUR objectives: - Examine and characterize energy transfer in food webs and chains. - Determine the ULTIMATE source of energy. - Examine feeding relationships at work in ecosystems
WHAT IS THE ULTIMATE SOURCE OF ENERGY FOR MOST FOOD WEBS AND CHAINS?
Trophic Levels Food chain- simple model that shows how matter and energy move through an ecosystem Direct Feeding Relationship
Trophic Levels Food web- shows all possible feeding relationships in a community at each trophic level Multiple Feeding relationships • Represents a network of interconnected food chains
Food chain Food web (just 1 path of energy) (all possible energy paths)
Trophic Levels • Each link in a food chain is known as a trophic level. • Trophic levels represent a feeding step in the transfer of energy and matter in an ecosystem.
Trophic Levels Biomass- the amount of organic matter comprising a group of organisms in a habitat. • As you move up a food chain, both available energy and biomass decrease. • Energy is transferred upwards but is diminished with each transfer.
Trophic Levels E N E R G Y Tertiary consumers- top carnivores Secondary consumers-small carnivores Primary consumers- Herbivores Producers- Autotrophs
Energy pyramid • At each trophic level 90% of the energy is USEDand only the remaining 10% is passed….so if you eat an apple 90% of the potential energy that the apple possesses is your body using it. • If an alligator were to eat YOU he would only get 1% of the apples potential energy.
THE POINT • ENERGY decreases as you move UP the food chain. • Video 1 • 2 • 3
Gotcha! • Video • Umm…song • Video 2 • hoot
Toxins in food chains- • While energy decreases as it moves up the food chain, toxins increase in potency. • This is called biological magnification Ex: DDT & Bald Eagles