25. Energy Flow

Question 1

trophic dynamics

Answer 1

the transfer of energy from one part of the ecosystem to another

Question 2

First Law of Thermodynamics

Answer 2

The total amount of energy in the universe is constant. Energy can be transformed, but not created.

Question 3

Second Law of Thermodynamics

Answer 3

Heat energy will move from a warmer body to a
cooler one. Thus entropy will increase over time
in a closed system.

Question 4

Limits on to the number of trophic levels

Answer 4

Energy losses limit number of trophic levels in ecosystems

Question 5

the 10% rule

Answer 5

Only 10% of energy consumed by a trophic level is assimilated and available to higher trophic levels

Question 6

Energy can move between ecosystems: allochthonous inputs of nutrients and energy

Answer 6

organic matter derived or created in a community external to the one it is deposited in

Question 7

trophic cascades

Answer 7

When a change in the population size of a species in one trophic level changes/alters populations in the other trophic levels.

Question 8

trophic levels

Answer 8

1. primary producers (autotrophs)
2. primary consumers (herbivores)
3. secondary consumers (predators)
4. tertiary consumers (predators)

Question 9

other limits to energy transfer

Answer 9

1. Can’t eat everything, and can’t find everything to eat

2. High trophic level individuals occur at lower abundances than lower trophic levels

Question 10

trophic cascade example

Answer 10

hunting of sea otters –> shifts system to ‘urchin barrens’ with low/no kelp