Biomass

Question 1

What is biomass? What is it measured in?

Answer 1

The dry mass of living material in living organisms. Measured as the dry mass of biological material in kg.

Question 2

How is biomass created?

Answer 2

The light energy from the sun is captured by green plants and algae during photosynthesis to make new biomass.

Question 3

How is biomass transferred?

Answer 3

Biomass is transferred from trophic level to trophic level.

Question 4

Why does the biomass transferred decrease along the food chain?

Answer 4

Biomass is lost/wasted due to DREU:

• Digestion
• Respiration
• Excretion
• Undigested parts of the consumed organism

Question 5

What increases the efficiency of a food chain?

Answer 5

A smaller number of organisms ina food chain increases its efficiency because the amount of energy or biomass available to be passed on from organism to organism is increased as there’s less biomass lost due to DREU factors.

Question 6

What is the difference between a pyramid of biomass and a pyramid of number?

Answer 6

Pyramid of biomass

• Each bar represents a trophic level
• Shows the amount of raw biomass in the form of glucose in each level (g/m^2)

Pyramid of number

• Each bar represents the amount of living organisms per trophic level
• Doesn’t necessarily show the greatest number of producers

Question 7

How do we calculate the efficiency of biomass transfer?

Answer 7

efficiency = average biomass in higher trophic level (g/m^2) / average biomass in lower trophic level (g/m^2)