Topic 12 Flashcards
what is an ecosystem?
communities of organisms interacting with their physical environment under the influence of environmental factors
what is ecosystem energetics?
the study of how energy is fixed by autotrophs and made available to heterotrophs
what are heterotrophs?
consummers
what are autotrophs?
producers
what is energy measured as?
The dry weight of organic matter in an
organism or ecosystem (tonnes C km -2)
what is the first trophic level?
primary producers
what is primary productivity?
The rate at which energy is fixed
what do primary producers carry out?
primary production
what do primary producers do?
fix inorganic nutrients into organic molecules
what is gross primary production?
total amount energy fixed into organic
molecules in an ecosystem
what is net primary production?
What the producer makes, minus what the
producer uses for itself
– The amount of energy for growth (Eproduction)
what is net primary production measured as?
biomass
what does net primary production tell us?
how much energy is available to other trophic levels
what are primary consumers?
herbivors
what trophic level are primary consumers?
second
what type of organism are primary consumers?
herbivores
what are primary consumers?
Organisms that consume the organic molecules of primary producers
what do primary consumers use to support their energy budget?
the energy consumed
what happens to the excess energy consumed in primary consumers?
its turned into new biomass
what is biomass production in the second trophic level called?
secondary production
what type of organism are tertiary consumers?
omnivores and carnivors
what trophic level are tertiary and secondary consumers on?
third and fourth
what are tertiary consumers?
Organisms that consume the organic molecules of consumers in a lower
trophic level
how do tertiary consumers support their energy budget?
they use the energy consumed
