1. Energy Flows What have you eaten today?
From where did that get its energy?
Did you get 100% of the energy from that?

2. Energy Flows
The flow of energy through an ecosystem is one of the most important factors that determines the system's capacity to sustain life.
Sunlight is the main energy source for life on Earth.
Energy is lost from systems in the form of lost heat, etc.

3. Trophic Levels - Producers
An autotroph or producer, is an organism that produces complex organic compounds (e.g. carbohydrates, fats, and proteins) from simple substances present in its surroundings, generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis).

4. Trophic Levels - Consumers
Heterotrophs or consumers are organisms that rely on other organisms for their energy and food supply.

5. Trophic Levels - Consumers
Different types of heterotrophs:
Herbivores
Carnivores
Omnivores
Detritivores (mites, earthworms, snails, and crabs, feed on plant and animal remains and other dead matter, collectively called detritus)
Decomposers

6. Trophic Levels – Energy Flows
Energy flows in one direction, from the sun or inorganic compounds to autotrophs (producers) to heterotrophs (consumers).
Food chain: a series of steps in which organisms transfer energy by eating and being eaten.

7. Trophic Levels – Energy Flows
A food web links all the food chains in an ecosystem together.

8. Trophic Levels – Energy Flows
Each step in a food chain or food web is called a trophic level.
Ecological pyramid: diagram that shows the relative amounts of energy or matter contained in each trophic level.
3 different types of ecological pyramids: energy pyramids, biomass pyramids, and pyramids of numbers.

9. Energy Pyramid
Only about 10 percent of the energy available within one trophic level is transferred to organisms at the next trophic level, e.g. one tenth of the solar energy captured by grasses ends up stored in the tissues of cows and other grazers.
On what trophic level are humans?

10. Biomass Pyramid
Usually measures kg/hectare

11. Numbers Pyramid
Measures number of organisms it takes to sustain an apex predator at each lower level.

12. Video: How the wolves changed the rivers
Food web
How

13. Yellowstone, Wyoming How the wolves changed the rivers https://www

14. Explain To your neighbor: How did the wolves change the ecosystem
Topic sentence
Supporting detail
Concluding sentence