Ecological Pyramids, Food Chain and Food Web

Ecological Pyramids, Food Chain and Food Web

by: Liwayway Memije-Cruz

What is an ecological pyramid?

• a graphical representation designed to show the biomass or productivity at each trophic level in a particular ecosystem.

Number Pyramid

• shows the number of organisms in each trophic level and does not take into consideration the size of the organisms and over-emphasizes the importance of small organisms. In a pyramid of numbers the higher up one move, so each consecutive layer or level contains fewer organisms than the level below it.

Biomass Pyramid

• shows the total mass of the organisms in each trophic level.

Energy pyramid. • shows the total amount of

energy present in each trophic level.

• indicates the loss of energy from one trophic level to the next.

• clearly illustrates that the energy transfer from one trophic level to the next is accompanied by a decrease due to waste and the conversion of potential energy into kinetic energy and heat energy.

Food Chain

• the feeding of one organism upon another in a sequence of food transfers .

• the chain of transfer of energy from one organism to another.

• the passage of energy from one tropic level to the next as a result of one organism consuming another.

• simply who eats whom.

GRAZING FOOD CHAIN

• one which goes from green plants to grazing herbivores and finally to carnivores.

DETRITUS FOOD CHAIN

• one, which goes from dead organic matter to microorganisms and then to detritus feeding organisms.

Food Web

• an interlinked food chains.