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Ecology. …the study of …….. OUR house…. …the study of how organisms interact with each other and their environments. MATTER CYCLES. FACTORS INTERACT. ENERGY FLOWS. ENERGY FLOWS. Trophic Levels. Energy moves from one organism to another when it is eaten
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Ecology …the study of …….. OUR house….. …the study of how organisms interact with each other and their environments
MATTER CYCLES FACTORS INTERACT ENERGY FLOWS
Trophic Levels • Energy moves from one organism to another when it is eaten • Each step in this transfer of energy is know as a trophic level • The main trophic levels are producers, consumers, and decomposers
When energy flows as organic matter through the trophic levels of an ecosystem, MUCH of it is LOST at each link in a food chain. Why? CLUE When you burn energy to run a mile in gym where does that energy come from?
Transfer of Energy • When a zebra eats the grass, it does not incorporate all of the energy the grass has into its body (much of it is not digested and used for energy to live)
Transfer of Energy • When a lion eats a zebra, it does not keep all of the energy from the zebra in its body….
Does all the energy this caterpillar eats get passed to the bird who eats him? Plant material eaten by caterpillar 100 kilocalories (kcal) 35 kcal Cellular respiration 50 kcal Feces 15 kcal Growth
Transfer of Energy • No organism EVER keeps all of the energy from the organism they just ate • Only ~10% of the energy from one trophic level is really transferred to the next – this is called the 10% law
Ecological Pyramid • An ecological pyramid shows the relationship between organisms different trophic levels in an ecosystem • Shows the relative amounts of energy or matter and number of organisms contained at each trophic level
Biomass • The total mass of the organic matter at each trophic level is called biomass • Biomass is just another term for potential energy – energy that has yet to be eaten and used.
What is a decomposer and what do they do? What trophic level would you put them at? • Derive their energy from the dead material left by all trophic levels • Are often left off of most pyramids and food chain diagrams Decomposers:
Ecological Pyramid • Which level has the most energy? • Which level has the most organisms? • Which level has the least organisms? • Which level has the least energy?