1. Energy Flow Through Ecosystems Chapter 5 section 1

2. 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

3. WHAT IS THE ULTIMATE SOURCE OF ENERGY FOR MOST FOOD WEBS AND CHAINS?

6. Trophic Levels
Food chain- simple model that shows how matter and energy move through an ecosystem
Direct Feeding Relationship

8. 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

9. Food chain Food web
(just 1 path of energy) (all possible energy paths)

10. 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.

13. 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.

14. E N R G Y Trophic Levels Producers- Autotrophs
Tertiary consumers- top carnivores
Secondary consumers-small carnivores
Primary consumers- Herbivores
Producers- Autotrophs

17. Energy pyramid
At each trophic level 90% of the energy is USED and 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.

21. THE POINT
ENERGY decreases as you move UP the food chain.
Video 1 2 3

22. Gotcha!
Video
Umm…song
Video 2
hoot

24. This is called biological magnification
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