1. The Ecosystem An Introduction S4L1b iCan demonstrate the flow of energy through a flood web/good chain, beginning with sunlight and including producerss, consumers, and decomposers.

2. Ecosystem A community of interdependent organisms and the interactions with the physical environment in which they live. A community of interdependent organisms and the interactions with the physical environment in which they live. It can also be defined as the abiotic and biotic factors and the interactions between them. It can also be defined as the abiotic and biotic factors and the interactions between them. The interaction between organisms and the environment is the key! The interaction between organisms and the environment is the key!

3. Differentiate between the following terms: Organism Organism Species Species Population Population Community Community Niche Niche Habitat Habitat

4. In your notebook, draw a picture of a bunch of little organisms Label: The organisms of the same type (species) Label: The organisms of the same type (species) Circle: individuals of the same species (Population) Circle: individuals of the same species (Population) Draw interactions between the populations (Community) Draw interactions between the populations (Community)

5. Compare the terms habitat and niche Sometimes people confuse these terms. Sometimes people confuse these terms. Figure out the differences between the terms. Figure out the differences between the terms.

6. Niche vs habitat A habitat is wear an organism lives. The habitat must provide a source of food, water and shelter for the organism. A habitat is wear an organism lives. The habitat must provide a source of food, water and shelter for the organism. Niche: The role of the organism. This is largely to do with the trophic level of the organism. Niche: The role of the organism. This is largely to do with the trophic level of the organism. For example: plants produce food for the rest of the food chain. Tigers keep herbivore populations under control. For example: plants produce food for the rest of the food chain. Tigers keep herbivore populations under control.

7. Abiotic and Biotic factors Biotic Factor: A living, biological factor that may influence an organism or a system. Biotic Factor: A living, biological factor that may influence an organism or a system. Example: predation, disease, competition Abiotic factor: A non-living, physical factor that may influence an organism or a system Examples: Temperature, salinity, pH, light

8. Which factors are biotic? Rabbits Rabbits Cacti Cacti Daylight hours Daylight hours Precipitation Precipitation Moss Moss Soil composition Soil composition Bacteria Bacteria

9. Limiting factors An abiotic factor can limit the population size if there is too much or too little of it. Even if there is the right amount of other factors An abiotic factor can limit the population size if there is too much or too little of it. Even if there is the right amount of other factors Examples to consider: Examples to consider:SunlightPrecipitationSalinity Nutrients in the soil

10. Trophic levels Ecostems are often broken up and described according to feeding relationships. Ecostems are often broken up and described according to feeding relationships. Trophic level: The position of an organism in a food chain The position of an organism in a food chain A group of organisms that occupy the same place in a food chain A group of organisms that occupy the same place in a food chain

11. Trophic levels in food chains Be able to give an example of each! Primary producers (autotrophs) Primary producers (autotrophs) Primary consumers (herbivores) Primary consumers (herbivores) Secondary consumers(carnivores) Secondary consumers(carnivores) Tertiary consumers (top carnivores) Tertiary consumers (top carnivores) Decomposers Decomposers Detrivores Detrivores Scavengers Scavengers

12. Energy flow and material cycling

13. Producer l Autotroph - “self” + “feed” l An organism that obtains organic food molecules without eating other organisms but by using energy from the sun or inorganic molecules to make organic molecules l Remember: This trophic level supports all of the others l The role of producers is to convert energy into a form useable for other organisms

14. Producers l Most producers are photosynthetic (e.g. algae, mosses, diatoms, some bacteria, plants etc.) but some are chemosynthetic (e.g. hydrothermal vent bacteria) (H 2 )

15. Decomposer l An organism that obtains energy by breaking down dead organic matter, including dead plants, dead animals and animal waste, into more simple substances l Examples include: bacteria and fungi L Interconnects all trophic levels since the organic material making up all living organisms is eventually broken down l Role of decomposers is to return valuable nutrients to the system so they can be used again

16. Compare detritus feeders to decomposers:

17. Consumer l Heterotroph - “other” + “feed” l An organism that obtains its nutrition by eating other organisms l Primary consumer (herbivore) - eats producers e.g. sea urchin, copepod l Secondary consumer (carnivore) - eats primary consumers e.g. wolf eel, herring l Tertiary consumer - eats secondary consumers e.g. sea otter, seal l Quaternary consumer - eats tertiary consumers e.g. killer whale

18. Consumers The role of the consumer is to transfer energy from one trophic level to the next. The role of the consumer is to transfer energy from one trophic level to the next. Notice that consumers have different names, depending on what they eat: Notice that consumers have different names, depending on what they eat: Herbivores: plant eaters Herbivores: plant eaters Carnivores: meat eaters Carnivores: meat eaters Omnivores: eat plants and animals Omnivores: eat plants and animals

19. Food Chains

20. Food webs Show energy flow through an ecosystem L An ecosystem’s trophic structure determines energy flow and nutrient cycling

21. Food webs

22. Trophic levels

23. Pyramid of biomass

24. Second Law of Thermodynamics There is a tendency for numbers and quantities of biomass and energy to decrease along food chains. There is a tendency for numbers and quantities of biomass and energy to decrease along food chains. The pyramids become smaller at the top because around 90% of the energy is “lost” between each level and only 10% is available in the body of the organism for transfer to the next level. The pyramids become smaller at the top because around 90% of the energy is “lost” between each level and only 10% is available in the body of the organism for transfer to the next level.

25. Energy transfer in a food chain: First law of thermodynamics

26. The end!