Food Chains Food Webs and Energy Pyramids Ecology

Food Chains, Food Webs and Energy Pyramids Ecology 6. f Chapter 22

The Food Chain…

Transfer of Energy • In a food chain: – Energy is passed from one link to another

When a herbivore eats… • Only a fraction of the energy is passed from one link of the food chain to the next.

Most of the Energy is… LOST “Or shall we say dissipated into the environment as heat. ”

Or used up through… Reproduction Digestion Movement

Therefore, when a herbivore…

is eaten by a carnivore…

only a small amount of energy passes.

This dissipation of energy… • Is represented in energy pyramids.

So why do they call it an Energy Pyramid?

What might go here? ? ?

What might go here?

Examples

Desert

Coniferous Forest

Deciduous Forest

Temperate Forest

Fluctuations in Populations Ecology 6 b & c Chapter 20

What might change a population? • • Birth Rate Immigration Emigration Death Rate

Birth Rate • Number of births occurring in a period of time.

Immigration • The movement of individuals into a population.

Emigration • Movement of individuals out of a population.

Death Rate or Mortality Rate • Number of deaths in a period of time.

What factors might change an ecosystem?

Changes in Ecosystems • • Population Size Climate Human Activity Introduction of Nonnative Species