3-2 Energy Flow

3-2 Topic Outline 3–2Energy Flow A.Producers 1.Energy From the Sun 2.Life Without Light B.Consumers C.Feeding Relationships 1.Food Chains 2.Food Webs 3.Trophic Levels D.Ecological Pyramids 1.Energy Pyramid 2.Biomass Pyramid 3.Pyramid of Numbers

Energy Flow Energy flows through Ecosystems  Sunlight or Chemicals  Producers  Consumers

Producers Key Concept:  Sunlight is the main source of energy for life on earth.  Some organisms rely on energy stored in inorganic chemical compounds

Producers=Autotrophs Plants, some algae, some bacteria can capture energy & produce food Essential step – captures energy and transforms it into organic, stored energy for the use of living organisms.

Energy Captured from the sun by  Photosynthesis Adds Oxygen to the atmosphere Removes Carbon Dioxide from the Atmosphere  Cyanobacteria

Energy Capture energy from the bonds of inorganic molecules  Hydrogen Sulfide Called: Chemosynthesis

Energy What is the difference between Photosynthesis & Chemosynthesis?

Consumers=Heterotrophs Consumers eat other organisms to obtain energy.  Herbivores  Carnivores  Omnivores  Detritivores  Decomposers Fungi & Bacteria

Feeding Relationships Key Concept:  Energy flows through an ecosystem in one direction – from producers to various levels of consumers

Feeding Relationships Food Chain  Simple Energy path through an ecosystem Food Web  More realistic path through an ecosystem

Trophic Levels Producers  Producers make up the first trophic level. Consumers  Consumers make up the second, third, or higher trophic levels.  Herbivores (Second Trophic Level ONLY!)  Omnivores (Second or Higher)  Carnivores (Third or Higher) Each level depends on the one below it for energy.

Go to Section: A Food Web

Ecological Pyramids Energy  Only about 10 percent of the energy available within one trophic level is transferred to organisms at the next trophic level. Biomass  The total amount of living tissue within a given trophic level is called biomass. Numbers  Ecological pyramids can also be based on the numbers of individual organisms at each trophic level.

Pyramid of Numbers Shows the relative number of individual organisms at each trophic level. Biomass Pyramid Represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the base of the pyramid. Energy Pyramid Shows the relative amount of energy available at each trophic level. Organisms use about 10 percent of this energy for life processes. The rest is lost as heat. Go to Section: Ecological Pyramids