III. Trophic Pyramids

Question 1

What does energy limit at each tropic level?

Answer 1

Biomass production

Question 2

How much energy is lost at each tropic transition?

Answer 2

~90%

Question 3

Tropic transfers in caterpillar example

Answer 3

Plant material is eaten by caterpillar w 200kcal (J), loses 100 kcal (J) as feces, uses 33kcal (J) for growth. (New biomass, secondary production), and 67kcal (J) is used for cellular respiration processes. Only 17% goes into creating new biomass, the rest is lost.

Question 4

What happens each trophic transition

Answer 4

The total energy available declines by 90% with each trophic transition

Question 5

What happens as you move up biomass pyramids?

Answer 5

As you move up the pyramid, biomass is lost

Question 6

Top down versus bottom up control

Answer 6

Organisms in different trophic levels are influenced from above by predation (top down) and from below by production (bottom up)

Question 7

Define bottom up control

Answer 7

Abiotic nutrients act as the primary determinant of trophic structure

Question 8

Define top down control

Answer 8

Predators act as the primary determinant of different abundance’s of organisms and different trophic levels