ecological productivity
what is primary production
rate at which producers (autotrophs) accumulate carbon compounds in their biomass
biomass accumulates as organisms grow or reproduce
whats primary production measured in
units of mass per unit area per unit time, such as grams per square metre
what does a higher producer biomass mean
it means that a higher number of organisms & a greater diversity of organisms can be supported
what does the rate at which primary producers accumulate biomass, depend on
depends on the region & season, as well as a couple factors, such as sunlight, temperature, precepiation
how is the primary production in regions with nutrient -rich soil, abundant sunlight & water
typically very high
remember - energy can be lost in producers through metabolic activities
not all the energy produced through photosynthesis is stored in biomass - some of it is used to fuel metabolic activities = energy loss
whats the gross primary productivity (GPP)
total amount of energy captured as biomass by primary producers
is basically the rate at which autotrophs convert carbon compounds into organic matter
whats the net primary productivity (NPP)
the amount of energy available for organisms in higher trophic levels
calculated by this equation - NPP=GPP-R
R = respiration rate
whats secondary production
rate at which heterotrophs (consumers) will accumulate carbon compounds as part of their own biomass
how is energy lost for consumers
in cell respiration, carbon compounds are converted into CO2 & H20
results in a loss of energy
is secondary production higher than primary production?
no, it’s lower than primary production
whats the gross secondary productivity (GSP)
total biomass assimilated by heterotrophs in an ecosystem
determined by measuring the total food consumed by organisms subtract the mass lost through faecal excretion
whats the net secondary productivity
energy available for higher tropic levels