Ecological Pyramids

Flashcards covering the topic of Ecological Pyramids including types, characteristics, the 10% Rule, and energy transfer.

What are ecological pyramids used for?

To show the relative amounts of material/energy at each trophic level.

How are the dimensions of an ecological pyramid determined?

They are proportional to the amount of material/energy at that level.

What are the three types of ecological pyramids?

Pyramids of numbers, biomass, and energy.

What does a Pyramid of Numbers show?

The number of all organisms at each trophic level.

Can a Pyramid of Numbers be inverted or spindle-shaped?

Yes, because of how the food chain is built and the size of the base organism.

Why might a Pyramid of Numbers be inverted?

A single large producer can support an entire food chain, or numerous parasites can live on a single host.

What does a Pyramid of Biomass show?

The dry mass of materials present in each trophic level.

Can a Pyramid of Biomass be inverted?

Yes, it is common in aquatic environments where producers and primary consumers are small.

What does a Pyramid of Energy show?

The amount of chemical energy present at each trophic level.

What units are typically used for a Pyramid of Energy?

kJ or kcal.

What is unique about the shape of a Pyramid of Energy and why?

It is always an upright pyramid because it illustrates the limit on energy transfer from one level to the next.

What is the 10% Rule in ecological energy transfer?

Only 10% of the energy in one trophic level makes it to the next.

How do you calculate the energy transferred to the next trophic level using the 10% Rule?

Multiply the energy in the current level by 0.10.

Where does the energy go that is not transferred to the next trophic level?

It is used by organisms for survival (finding food, water, shelter, mating), lost from organisms in chemical bonds (CO2, urine, feces), or radiated as heat.