Flow of Energy through Ecosystems

• Food Chain: A simple diagram of one string of feeding relationships in an ecosystem, showing the direction of the transfer of energy in that system.

Sun Grass Rabbit Wolf Bacteria

Soil

Producer

• Organisms that make their own food from inorganic molecules and energy. – eg. Plants, blue-green algae – Most accomplish energy building through

photosynthesis

Consumers

• Organisms that cannot make own food. – eg. all animals, fungi and most bacteria – Obtain energy by eating other organisms this

process is called cellular respiration

Consumers…

• Primary consumer (10) – eats plants (aka herbivore)• Secondary consumer (2o)– eats a primary consumer• Tertiary consumer (3o)-eats a secondary

consumer

Consumers cont…

• Omnivores—eat both producers and consumers

• Scavenger—usually don’t hunt live prey—feed on bodies of dead organisms

Decomposers

• Bacteria and fungi that break down organic material; essential to ecosystem health because they recycle nutrients back for producers to reuse.

Food Web

• a group of food chains showing all of the feeding relationships in an ecosystem.

• Trophic level—a layer in the feeding relationship of an ecosystem, one link in the food chain/web.

Food Web

Man Wolf Sheep

BacteriaRabbit Mice Deer

Grass Flower Carrots

Nutrient Rich Soil

Sun

Fox

Things to remember…

•The sun…energy starts here. ALWAYS!•Decomposers (fungi and bacteria)…energy is

recycled here. ALWAYS!•Put all the animals on the same trophic level on a horizontal line (producers together, then primary

consumers, then secondary consumers, etc.)•Make as many connections between your

organisms as you can. Everything should have at least one food source and be eaten by at least

one thing.