Energy Flow in Ecosystems

All Organisms Need Energy To Survive! Some organisms get energy by making it themselves These organisms are called autotrophs

All Organisms Need Energy To Survive! Some organisms get energy from other organisms These organisms are called heterotrophs

Autotrophs Another word for autotroph is producer Examples of autotrophs include grass, algae and trees Autotrophs make their own energy (food) by using the sun’s energy to convert water and carbon dioxide into a form of food that they can use called glucose This process is called photosynthesis

What Happens to all the Energy Made by Autotrophs/Producers? They use most of it to carry out their functions (growing, reproducing, etc.) Some of it is lost in the atmosphere as heat Only 10% of the energy is available for the organisms that eat them

Heterotrophs Another word for heterotroph is consumer Examples of heterotrophs include dogs, fish, elephants, and mushrooms Heterotrophs get their energy by consuming/eating other organisms There are many different types of heterotrophs/consumers…

Heterotrophs Primary Consumers only eat plants (herbivores) Secondary Consumers eat primary consumers (carnivores/omnivores) Tertiary Consumers eat secondary consumers (carnivores/omnivores) Scavengers feed off of dead consumers Decomposers feed by breaking down organic matter from dead organisms

What Happens to all the Energy Consumed by Heterotrophs? They use most of it to carry out their functions (growing, reproducing, etc.) Some of it is lost in the atmosphere as heat Only 10% of the energy is available for the organisms that eats them

Food Chains Food chains show the transfer of energy from the sun to producer to consumer Arrows point in the direction that the energy is going 9

Food Webs Very rarely in nature is the transfer of energy in an ecosystem as simple as a single food chain Food webs are interconnected food chains that show feeding relationships of many organisms in an ecosystem 10

Food Webs 11

Energy Pyramids An energy pyramid is yet another way of showing the transfer of energy in an ecosystem Each level is called a trophic level They also show How amount of available energy decreases for higher consumers That it takes a large number of producers to support a small number of tertiary consumers

Energy Pyramids