Food Chains, Webs, & Pyramids How Energy Flows in an Ecosystem Producers, Consumers, and… FOOD CHAINS Producers • A group of organisms that produce their own food using sunlight to convert water & CO2 into glucose (food) – Also called autotrophs – Examples: plants & algae Producers/Autotrophs Consumers • Organisms that consume other organisms in order to live – Also called heterotrophs because they cannot make their own food – Examples: sharks, mushrooms, seals, cows Consumers/Heterotrophs Primary Consumers • Eat plants – Examples: giraffes, rabbits Primary Consumers Secondary Consumers • Eat primary consumers (eat plant eaters) – Examples: lions, tigers, bears (oh my!) Secondary Consumers Tertiary Consumers • Eat secondary consumers (eats meat eaters) – Examples: cougars, bears, wolves – Not always present in the food chain Tertiary Consumers Scavengers • Feed on the tissue of dead organisms (both plants and animals) – Examples: crows, vultures, shrimp Scavengers Decomposers • Absorb any dead material and break it down into simple nutrients or fertilizers – Examples: bacteria & mushrooms Decomposers Food Chain • A diagram that shows how energy in food flows from one organism to another – Arrow points toward whichever organism is receiving the energy Food Chain Links in the Chain • Every organism depends on the other organisms – Example: If all of the grass died, the grasshopper would starve to death causing the snake and the hawk to starve to death until eventually even the fungi do not have anything to feed on Chains + Chains = FOOD WEBS Food Webs • A diagram that shows the feeding relationships between organisms in an ecosystem – Multiple relationships composed of multiple food chains – Most organisms eat more than one organism – Much more complex and accurate Food Web How energy flows… ENERGY PYRAMIDS Energy Pyramid • A triangular diagram that shows an ecosystem’s loss of energy – Results as energy passes through the ecosystem’s food chain/web – Shows the number of organisms and amount of matter/energy available at each level – Decreases at each level because most energy is lost as heat waste The End!