8: Matter and Energy in Ecosystems

Question 1

Is matter recycled in an ecosystem?

Answer 1

YES! matter is recycled between abiotic and biotic factors by the actions of decomposers

Question 2

What happens to energy with each transformation?

Answer 2

with each transformation some of the energy from the sun is converted to low quality energy (heat)

Question 3

What is the 10% rule?

Answer 3

only 10% of the energy at the trophic level reaches the following trophic level; the other 90% of the energy is “lost” from one trophic level to the other (not lost to the universe, but lost to the ecosystem as heat)

Question 4

Is energy recycled in an ecosystem?

Answer 4

NO, energy follows a one-way flow

Question 5

What law explains the unidirectional flow of energy in the ecosystem?

Answer 5

the second law of thermodynamics

Question 6

What is a food web?

Answer 6

it is a more realistic representation of the trophic relations in a community than a food chain; every population has many choices in terms of feeding resources