Ecological Pyramids

Trophic levels Trophic levels describe the various stages within ecological food chains or webs.

5 course meal! Primary Producers Primary Consumers Secondary Consumers Tertiary Consumers Decomposers

How trophic levels work Pyramids: Trophic levels Food Chains

Primary Producers photosynthetic or chemosynthetic organism that Definition: A photosynthetic or chemosynthetic organism that synthesizes complex organic molecules from simple inorganic ones. These are usually referred to as AUTOTROPHS

Primary Consumers An herbivore An Omnivore Definition: An organism that feeds on producers An herbivore These gain their energy from eating plants. An Omnivore These gain their energy from eating plants or animals

Secondary consumers A carnivore Definition: An organism that eats primary consumers A carnivore These get their energy by eating other animals

Tertiary Consumers Definition: An organism that eats secondary consumers

Decomposers Definition: Organisms, such as many bacteria and most fungi, that play beneficial roles in all ecosystems by breaking down and absorbing nutrients from dead and decaying organic matter

What about humans? Humans screw it up again!!! Humans can fit in 3 of the 5 categories depending on diet.

Pyramids Three pyramids that we use in Ecology Pyramid of Numbers Pyramid of Biomass Pyramid of Energy

Pyramid of Numbers This pyramid is constructed by taking the population statistics of each of the trophic levels. Notice how the numbers drop significantly between levels.

Pyramid of Biomass Biomass is calculated using the combined weight of all species of plants and animals that may exist within an ecosystem.

Pyramid of Energy Energy is passed from one level to the next. Notice the approximate loss of energy between the levels.

Rule of 10’s When progressing up the pyramid of energy there is a 90% drop in the amount of energy between levels. Example: If we start with the primary producer containing 1000 units of energy how much energy will be present for the tertiary consumer?

Primary Producers= 1000 units of energy Primary Consumers= 100 units of energy Secondary Consumers= 10 units of energy Tertiary consumers= 1 unit of energy It takes the energy of 1000 plants to feed a tertiary consumer 1 unit of energy!

Conclusion