Energy Flow in EcosystemsTerms to know:Producers (autotrophs):Organisms, like green plants, thatproduce organic compoundsfrom inorganic compounds.Consumers (heterotrophs):Organisms that obtain nutrientsfrom other organisms.Decomposers:Organisms that break down the remainsof dead animals and plants, releasing thesubstances that can be used by othermembers of the ecosystem.
Energy Flow in EcosystemsAlmost all energy onEarth comes fromradiant energy – theenergy from our sun.
Energy Flow in EcosystemsRadiant energy that isabsorbed by land andwater is called thermalenergy. It keeps Earthat its presenttemperature range.
Energy Flow in EcosystemsThe portion of radiant energy we can see is called lightenergy.
Energy Flow in EcosystemsProducers can collect this energy and turn it intochemical energy.
Energy Flow in EcosystemsThis process is called photosynthesis:carbon dioxide + water + light energy sugar + oxygenSugar is a source of high energy.
Energy Flow in EcosystemsWhen a consumer eats a producer, it releases the energyfrom the sugar in a process called cellular respiration:sugar + oxygen carbon dioxide + water + energy
Food Chains"Theres always a bigger fish."– Qui-Gon Jinn
Food ChainsA food chain is a diagram which shows how organismsare linked together by feeding relationships.seed mouse cat
Food ChainsA food chain is a diagram which shows how organismsare linked together by feeding relationships.
Name an organism that:- eats rabbits- is on trophic level 2- is an autotroph- is a top carnivoreThink. Pair. Share.
Impacts on Food WebsWhat would happen if an organism in a food chainsuddenly has a drastic change in population?
Think. Pair. Share.What would happen if allof the mangroves in thisecosystem were cut downby humans?There would be no foodfor the fish or crabs toeat, so they would all dieoff.After the fish and crabs die,the seabirds and piedoyster catchers would alsostarve.
What would happenif a virus invadedthis ecosystem andkilled-off all of theseabirds?There would be nopredators to eat thefish and the fishpopulation wouldbecome very large.If there are too manyfish in the ocean, theymay out-compete thepied oyster catchersfor crabs and drivethem to starvation.Think. Pair. Share.
Ecological PyramidsNo organism EVER receives all of the energyfrom the organism they just consumed.
Ecological PyramidsOnly 10% of the energy from one trophic level istransferred to the next (most of the energy islost as heat)
Ecological PyramidsAn ecological pyramid shows the relationship betweenproducers and consumers at different trophic levels inan ecosystem by relative amounts of energy or matter
1) Pyramid of Numbers:- show number of organisms in each trophic level- usually numbers decrease as one moves up food chain10 000 grass900 ants5 birdsEcological Pyramids
Sometimes, it does not produce a proper pyramid in allcases1500 lice4000 caterpillars1 tree5 birdsEcological Pyramids
2) Pyramid of Biomass:- The total mass of the organic matter at each trophiclevel is called biomass- Biomass is just another term for potential energy –energy that is to be eaten and used.Ecological Pyramids2 kg lice15 kg birds200 kg caterpillars2000 kg apple tree
10 kJ birds100 kJ caterpillars1000 kJ apple tree1 kJ lice3) Pyramid of Energy:- show the total energy of organisms in a food chain- this is the best way to show flow of energy through afood chainapprox. 90% energy is lost with each transfer in the food webEcological Pyramids