1. Energy Flow How does energy move through the ecosystem? http://www.armofthesea.info/images/landscapes/crommet_lg.jpg

2. How does Energy Flow through Ecosystems? All organisms require energy for life processes. Growth Hence for all organisms there must be: A source of energy A loss of usable energy This energy is used or lost and is not available if consumed Locomotion What do you mean by life processes? Reproduction

3. Conservation: • Law of Conservation of Matter - • Matter cannot be created nor destroyed, only transformed from one form to another.

4. First Law of Thermodynamicsalso called… • Law of Conservation of Energy - • Energy can be converted from one form or another but cannot be created nor destroyed, only transformed from one form to another.

5. How does energy flow through a food chain? • Food Chain: A simple diagram of one string of feeding relationships in an ecosystem, showing the direction of the transfer of energy in that system. Sun Grass Rabbit Wolf Bacteria Soil

6. Energy: • 2nd Law of Thermodynamics: • When energy is changed from one form to another, some energy will be lost to the larger environment. • Nothing is ever 100% efficient. • This is due to entropy (nature’s tendency towards randomness).

7. 2nd law of thermodynamics in action: When energy is changed from one form to another, some energy will be lost Why? Rabbit moves, respires, grows, etc.. Energy is used, no longer available if eaten. Sun Grass Rabbit Wolf Bacteria Soil

8. What are the parts of a food chain? Producers • Organisms that make their own food from inorganic molecules and energy. • eg. Plants, blue-green algae • Most accomplish energy building through photosynthesis Inorganic Molecules = molecules that are not part of a living organism Energy is almost always from the sun (very rare exceptions) Water + Carbon Dioxide + Sunlight Sugar + Oxygen

9. Consumers • Organisms that cannot make own food. Consumers are: all animals, fungi and most bacteria They must obtain energy by eating other organisms — through a process called cellular respiration Sugar + Oxygen  Carbon Dioxide + Water +ATP (energy)

10. Decomposers • Bacteria and fungi that break down organic material Decomposers are essential to ecosystem health because they recycle nutrients back for producers to reuse.

11. What is a Food Web? • a group of food chains showing all of the feeding relationships in an ecosystem.

12. Food Web Sun HumanWolfFox Sheep Bacteria RabbitMiceDeer GrassFlowerCarrots Nutrient Rich Soil

13. Many toxins in the person Many toxins in the water Biological Magnification • Increasing concentration of a substance in the tissues of organisms in the higher levels in a food chain or web. (Nearly always something dangerous, like a toxin)

14. Biological Magnification- accumulation of increasing amounts of toxin within tissues of organisms. Video on Biological Magnification

15. Trophic Levels So, all producers are at the same trophic level and all primary consumers are at the next trophic level. • Trophic level — a layer in the feeding relationship of an ecosystem, one link in the food chain/web. • Biomass — total amount of organic material present in a trophic level. Organic = is currently living or lived in the past

16. Energy Pyramids • Another way to look at trophic levels. • a diagram showing the relative amounts of energy/biomass in the different trophic levels. • Lowest trophic levels are at the bottom: Producers have the greatest biomass. http://www.vtaide.com/png/foodchains.htm http://www.earthforce.org/files/1284_image2_Energy_Pyramid_for_Galvbay.jpg

17. Example of an Energy Pyramid 1 pound MAN 10 pounds FOXES 100 pounds RABBITS 1000 pounds of GRASS MAN 0.1% Energy Lost during conversion to heat, waste…. 10% 100 % of the sun’s energy FOX 90% 1% 10% Rabbit RABBIT 90% 10% 10% Grass 90% - The decreasing size of the pyramid shows that each level of the pyramid has a smaller and smaller number of those organisms.