5.3 ENERGY & ECOSYSTEMS Flashcards
What are producers?
They manufacture organic substances by photosynthesis.
What are consumers?
Obtain their energy by feeding on other organisms rather than using sunlight.
What are saprobionts?
Organisms that obtain energy by breaking down complex organisms in dead matter into simple matter.
What is productivity?
The total mass of living matter (biomass) in a given area at a given time.
How is biomass formed?
The biological molecules synthesised by producers/consumers.
How do you measure biomass?
As the chemical energy store of dry biomass.
How do you measure the chemical energy store?
Use calorimetry, by seeing how much energy is produced when the ‘biomass’ is burned.
What is primary productivity?
The rate at which energy is converted into organic substances by producers.
What is secondary productivity?
The rate at which biomass is formed in consumers.
What is the gross primary production? (GPP)
The total chemical energy of a plant’s biomass.
What is the net primary production? (NPP)
The chemical energy store of biomass after respiratory losses.
How do you find the NPP?
NPP = GPP - R (respiratory losses)
Roughly how much energy is lost during respiration in producers?
40%
Why is the whole NPP not transferred to the consumer at the next trophic level?
- Some lost as faeces/urine.
- Some lost to heat.
- Not all is digested/consumed.
How do you calculate the net production of consumers?
N = I - ( F + R)
I = ingested feed energy. F = losses to faeces. R = respiratory losses.
