TROPHIC LEVELS & ENERGY FLOW
Trophic = Food
each step in a food chain or food web Trophic Level each step in a food chain or food web
It all BEGINS with the SUN Sunlight is the main energy source for life on Earth Less than 1% is used by living things.
1st Trophic Level Producers Organisms that can capture energy from sunlight (photosynthesis) or chemicals (chemosynthesis) and use it to produce food from inorganic compounds Known as autotrophs Examples Plants Some algae
Photosynthesis a process by which plants and some other organisms use light energy to convert water and carbon dioxide into oxygen and high-energy carbohydrates
Photosynthesis Carbon dioxide + Water Carbohydrates + Oxygen Light Energy Carbon dioxide + Water Carbohydrates + Oxygen
Chemosynthesis a process by which some organisms such as certain bacteria, uses chemical energy to produce carbohydrates
Chemosynthesis
The Next Trophic Levels Consumers Organisms that rely on other organisms for their energy and food supply Cannot make their own energy Known heterotrophs Different types of heterotrophs Herbivores Carnivores Omnivores Decomposer
Herbivores Organisms that obtain energy by eating only plants Known as 1st Level Consumer Examples Cows Caterpillars Deer
Carnivores Organisms that obtain energy by eating only animals Could be 2nd or 3rd Level Consumers Examples Snakes Owls Bobcats
Omnivores Organisms that obtain energy by eating both plants and animals Could be 2nd or 3rd Level Consumers Examples Humans Bears Crows
Detritivores Organisms that feed on plant and animal remains and other dead matter Similar to decomposers Example Earthworms Snails crabs
Decomposers Organisms that break down and obtains energy from dead organic matter Example Mushrooms (fungi) Bacteria 15
Energy Flow Only about 10% of the energy available within one trophic level is transferred to organisms at the next trophic level. The rest of the energy is lost as heat.
Energy Flow
Energy & Biomass Pyramid PRODUCERS 1st Level CONSUMERS 2nd Level CONSUMERS 3rd Level CONSUMERS SUN 0 % ENERGY LEFT Decomposers Herbivores & Omnivores Carnivores & Omnivores Plants
Energy & Matter Cycle (90%) (90%) (90%) Chemicals Producers (What ever is left) Heat Chemicals Sun Basic elements of life: Sulfur, Phosphorus, Oxygen, Nitrogen, Carbon & Hydrogen (90%) Heat Producers Decomposers Bacteria, Moss, Mushrooms, etc. Consumers (90%) Heat (90%) Heat
Exit Card What is an omnivore? Give me an example. What is the process called when plants use light energy to convert CO₂ and water into carbohydrates and O₂? What is the percentage of available energy within one trophic level that to be transferred to an oraganism at the next level? What is a producer? Give me an example.