energy flow in ecosystems Flashcards
(19 cards)
what does an ecosystem include?
all the biotic and abiotic facotrs
what are primary producers?
organisms that make their own glucosew
where do terrestrial plants get their CO2 from?
the atmosphere
where do aquatic plants get their CO2 from?
CO2 dissolved in the water
how does the food chain go?
producer –> primary consumer –> secondary consumer –> tertiary consumer
–> quaternary consumer
what do the arrows show in a food chain?
the flow of energy or the transfer of biomass
what is biomass?
the mass of living matter of the organism or tissue
the chemical energy stored in an organismi
in what terms can biomass be measured?
the dry mass of an organism or tissue
the mass of carbon in an organism
what is gross primary productivity (GPP)?
the storing of chemical energy as plant biomass in a given area
how can GPP be expressed?
g m^-2
kg m^-2
J m^-2
kJ m^-2
why are not all the products from photosynthesis used to form new plant biomass?
- used up in respiration to release energy and some of the energy is lost as heat
- this is known as respiratory loss (R)
what is the net primary productivity (NPP)?
the chemical energy left over after respiratory loss
how can NPP be calculated?
NPP = GPP - R
what does productivity mean?
the rate of production
how can primary and secondary productivity be expressed?
mass/energy per unit area of unit time
e.g. g m^-2 day^-1
J m^-2 day ^-1
what is secondary production?
when consumers ingest other organisms, the chemical energy in the biomass if these organisms is transferred to the consumer
why is not all of the chemical energy in the consumers food transferred to them?
- not all of the biomass is eaten
- consumers aren’t able to digest 100% of the good they ingest so some is always egested as faces
- lots of chemical energy is lost to the environment when the consumer respires (mainly lost as heat) and during excretion of waste products
what is the net production of consumers?
energy left after all the losses are accounted for
how can the net production of consumers be calculated?
N = I - ( F + R )
I = chemical energy store in ingested food
F = chemical energy lost in feces and urine
R = respiratory losses
