Energy flow through Ecosystems

Producers

• Use energy from the sun and convert it to Chemical energy through photosynthesis.

• Also known as Autotrophs or “self-feeders”

• Includes plants, some bacteria and photosynthetic protists such as phytoplankton.

• CO2+H20 C6H12O2 + O2

Consumers

• Organisms that must get their energy by eating other organisms.

• All animals are consumers.

• Also know as Heterothrophs, because they must get their nutrients from an outside source.

• Different degrees of Consumers

Primary Consumers

• 1o Consumers are animals that eat plants.

• All Herbivores are 1o Consumers

Secondary Consumers

• Animals that eat Primary Consumers

• Carnivores that eat herbivores are 2o consumers

• Examples :

cougar eat deer

Bird eating a grasshopper

Tertiary Consumer

• A carnivore that eats and animal that eats animals that eats plants are 3o consumers

Examples:

-Hawk eats the bird that ate the grasshopper

-A fish that ate a fish that ate algae

3o consumers are susceptible to toxins building up in the food chain.

Quaternary Consumer

• Animals that eat animals that eat animal that eats animals that eats plants are 4o consumers.

A killer whale that eats a seal that ate a fish that ate krill that ate plankton is an a 4o consumer.

Energy is lost

• At each trophic level energy is lost as heat and waste, so only between 1-10% of the energy consumed is available to the next level.

• If 10,000 units of energy come from the sun…

• Most of the energy from the sun is absorbed as heat or is reflected by the atmosphere.

• So plants only get to use about 10% of the 10,000 units of energy or about 1000 units.

• The herbivores only get about 10% of that as plants use a lot of energy in their growth and maintenance. So they get about 100 units

• So by the time a quaternary consumer comes along, there is only 0.1 units of energy left. Not much!

.01 units

1 unit

10 units

100 units

1000 units

• That’s why there are fewer carnivores than herbivores in an ecosystem. As energy passes through the trophic levels, energy is lost as heat and waste at each level.

• So there may be 200 or more deer in the range of one mountain lion.

Food Webs

Sun

Grass/Seeds Pinion/nutsJuniper/Berries

Ants Mouse Deer

Horned Lizard Coyote Bear

Cougar