1. The Principles of Ecology

2. Ecology  The study of how living things interact with each other and with their environment  By necessity it overlaps with geology, geography, climatology and other sciences.  An organism is an individual living thing  Like every other organism all organisms have two basic needs  ENERGY AND MATTER

3. Ecology  Matter and energy are obtained from the environment  Organisms depend on and are influenced by their environment  Contains two kinds of factors  Biotic – living things  Other organisms as well as members of the same species  Abiotic – nonliving aspects  Sunlight, Soil, Temperature, Water

4. The Ecosystem  A unit of nature and the focus of the study of ecology  All the biotic and abiotic factors in an area and how they interact with each other  They vary in size  Lake  Dead log

5. Ecosystems and Energy  These are not closed systems  They need inputs of energy  Most comes from sunlight  A small amount comes from chemical compounds  Matter is not constantly added to an ecosystem  Matter is recycled  Water, Carbon, Nitrogen, Phosphorus

6. Niche  Refers to the role of a species in its ecosystem  Includes the way the species interacts with the biotic and abiotic factors of the environment.  The niche of a species  The food it eats and how the food is obtained

7. Bird Niches

8. Habitat  This is the physical environment in which a species lives and to whit it is adapted  Mainly determined by abiotic factors  Temperature and rainfall  These factors also influence the traits of the organisms that live there

9. Competitive Exclusion Principle  A given habitat may have many different species, but each species must have a different niche.  Two different species cannot occupy the same niche in the same place for very long.  This is know as the competitive exclusion principle  They compete for the same food and other resource found in the environment

10. Competitive Exclusion Principle

11. Flow of Energy  Energy enters in the form of sunlight or chemical energy  Some organisms use the energy to make food  Other organisms get energy by eating food

12. Producers  Produce food for themselves and other organisms  They are called autotrophs  Photoautotrophs  Plants, Algae, and Bacteria  Chemoautotrophs  Some bacteria, archea

14. Chemoautotrophs

15. Consumers  Depend on other organisms for food  All animals and fungi  Many Bacteria  Some plants  Called Heterotrophs  Herbivores  Consume producers  Deer, Rabbits, Mice  Carnivores (Obligate carnivores-can’t eat plants  Consume animals  Omnivores  Eat both plants and animals

16. Decomposers  Break down the remains and other waste and release simple inorganic molecules back into the environment  Scavengers – consume the soft tissues of dead animals  Vultures, Raccoons, and Blowflies  Detritivores – consume detritus  Dead leaves, animal feces, and other organic debris  Earthworms, Millipedes, dung beetles on land  Bottom feeders in water like sea cucumbers and catfish  Saprotrophs – feed on what’s left  Fungi, single-celled protozoa

17. The Ultimate Recyclers  http://science.kqed.org/quest/video/scie nce-on-the-spot-banana-slugs-unpeeled/ http://science.kqed.org/quest/video/scie nce-on-the-spot-banana-slugs-unpeeled/

18. Food Chains and Food Webs  They Show Who eats Whom  Food Chains  Represent a single pathway through which energy and matter flow through an ecosystem  Food chains are generally simpler than what really happens in nature  Typically not a one-on-one relationship

19. Food Chain Where would you add the decomposers to this picture? http://www.youtube.com/watch?v=TE 6wqG4nb3M

20. Food Webs  Represents multiple pathways through which energy and matter flow through the ecosystem  Includes many intersection food chains  Shows that most organisms eat, and are eaten, by more than one species.

21. Food Web

22. Trophic Levels  The feeding positions in a food web are called trophic levels  Most food webs have 2-3 trophic levels with a typical maximum of 4 levels

23. Trophic Levels Trophic LevelWhere it Gets Food Example 1 st – These are the producers Make their own food Plants 2 nd Trophic Level – Primary Consumers Consume Producers Mice eat plants 3 rd Trophic Level – Secondary Consumers Consume Primary Consumers Snakes eating mice 4 th Trophic Level – Tertiary Consumers Consumer Secondary Consumers Hawks eat Mice

24. Trophic Levels and Energy  Only about 10% of the energy from one level is available for the next level  So: What happens to the other 90%  Used for metabolic processes  Given off to the environment as heat  This is called the 10% rule

25. Energy Pyramid

26. Trophic Levels and Biomass  With less energy available to higher trophic levels there tend to be fewer organisms on those levels  Organisms at the higher trophic levels also tend to be larger in size  Biomass is the total mass or organisms at a trophic level

27. Ecological Pyramid

28. Summary  Ecology is the study of how living things interact with each other and their environment. The environment include abiotic and biotic factors  An ecosystem consists of all the biotic and abiotic factors. A niche refers to the role of a species in its ecosystem. A habitat is the physical environment in which a species lives and to which it is adapted. Two different species can’t occupy the same niche in the same place for very long.

29. Summary, Continued  Ecosystems require constant inputs of energy from sunlight and chemicals. Producers use energy and inorganic molecules to make food. Consumers take in food by eating producers or other living things. Decomposers break down dead organisms and other organic wastes and release inorganic molecules back to the environment

30. Summary Continued One More Time  Food chains and food webs are diagrams that represent feeding relationships. They model how energy and matter move through an ecosystem.  The different feeding positions in a food chain or web are called trophic levels. Generally, there are no more than four trophic levels because energy and biomass decrease from lower to higher levels.