intro ecology ocs biology

1. ecology ENERGY IN ECOSYSTEMS

2. Ecology Ecology is the study of how organisms live and interact in their environment. The term ecology literally means “study of the household” so if you are studying the ecology of fish, you are studying fish neighborhoods!

3. Community and Habitat A habitat is a particular place where organisms live. Forests, ponds or coral reefs are all examples of a habitat. Your backyard can be a habitat. Theorganismsin the habitat are community members. These organisms are community members of a pond habitat.

4. Community and habitat The habitat is like a neighborhood. The community is like the people.

5. ECOSYSTEMS An Ecosystem is made up of groups of organisms and their physical environment. Environment is everything living and nonliving that surrounds an animal. Can you name some of the things in this bears environment?

6. ECOSYSTEMS Living things depend on each other for energy. Plants get their energy from the sun, some animals get their energy from plants, and others get their energy from other animals.

7. ENERGY IN ECOSYSTEMS Most of the energy in an ecosystem comes from the sun. Organisms called producers take in that energy and store it in their cells. You have already studied that process, it is called photosynthesis. Producers include plants, some bacteria and algae. See some on the next slide!

8. PRODUCERS

9. ENERGY IN ECOSYSTEMS Everything else in an ecosystem is called a consumer. Consumers get their energy by consuming other organisms. They can’t make their own food. In an African Grassland habitat, Acacia trees are producers, and giraffes and lions are consumers.

10. CONSUMERS

11. ENERGY IN AN ECOSYSTEM There are 3 main groups of consumers:

12. ENERGY IN AN ECOSYSTEM

13. ENERGY IN AN ECOSYSTEM

14. ENERGY IN ECOSYSTEMS In every ecosystem there are also some consumers known as decomposers. Decomposers get their energy by consuming wastes (fallen leaves, dead bodies, feces). In an African Grassland habitat, dung beetles and fungi are the decomposers.

15. ENERGY IN AN ECOSYSTEM Consumers are sometimes separated into levels. First level consumers are animals that eat producers. These are herbivores. Second level consumers are either carnivores or omnivores and they eat first level consumers. Third level consumers eat second level consumers. See the next slide to learn more about the different levels of consumers.

16. 2ND LEVEL CONSUMER 1ST LEVEL CONSUMERS PRODUCERS

17. ECOSYSTEMS Can you identify…. The producer? Grasses The first level consumer? Cricket The second level consumer? Frog

18. ENERGY IN AN ECOSYSTEM Energy flows from the sun to the producers to the consumers. This path is called a FOOD CHAIN

19. In a food chain energy is passed from one animal to another. When an herbivore eats, like a giraffe eating twigs, only some of the energy stored in the leaves is used by the giraffe to grow, the rest is lost as waste, or is used up in life processes like digestion, reproduction and movementSo….

20. When a carnivore, like the cheetah, eats the giraffe, only a little of the energy is passed on to the cheetah. Remember, some energy was already lost by the giraffe, so there is less for the cheetah.

21. And the cheetah will lose some energy too. The cheetah will have to eat more of the herbivores to get enough energy to survive. Producer 1st level consumer 2nd level consumer

22. When we look at energy in a food chain we sometimes make an energy pyramid. Notice how you start out with a lot of producers (acacia trees and grasses), and then have fewer 1st level consumers and even fewer 2nd level consumers.

23. A food web looks at many more parts of the ecosystem. It shows how several animals interact with each other. In food chains on earlier slides we looked at only trees, giraffes and a cheetah. But there are many more producers and consumers in the African Savannah. FOOD WEBS A food web shows how the cheetah can consume more than just a giraffe, and that there are more than just trees as producers. It is more complex.

24. FOOD WEBS Can you follow what eats what?

25. BALANCE IN THE ECOSYSTEM A problem in one part of the food web can cause problems in all of it. Imagine what would happen if there were no trees in this picture. What would happen to the giraffes? What would happen to the lions?

26. BALANCE IN THE ECOSYSTEM This is why all of the planet’s resources are so important. We must learn to respect nature and not upset the balance through human activities.

27. BALANCE OF THE PLANET Afterall, man is just one small part of the planet’s giant ecosystem. Learn more about this in your next module on Cycles of Matter.

29. Ecosystems include organisms and their surroundings

30. Organisms can be producers or consumers

31. Producers are mainly plants, algae and some bacteria