unit 5 B Flashcards
what is biomass
it is the measure of drymass or the amount of carbon an organims contains
how do we mesure biomass
dry mass is calculated through removing all the water an organims contains(dried), heating it at a low tempreture and checking it in regular intervals; if the mass remians constant all the water has been removed, the dry mass is said to be 50 percent of the carbon it contains. scale up the reuslts for the population or area being investigated
mesured in kg m-2
calorimtery
is is the measure of the chemical energy store in the biomass and can be measured through burning the biomass; a knwon body of water is placed above the organism which is being burned and the change of water tempreture is the amount, heat energy, being released is the amount of chemical energy is conatined in the biomass
what is GPP
gross plant production; the amount of light energy that it converted into chemical energy by plants in a given area , however the GPP 50 percent is lost to the enviroemnt when plants respire as heat energy.
what is NPP equation
npp= gpp - r
how do we express primary production as a rate
kj m-2 y-1
what is NPP used for
repsiration and growth for a plant
stored in the plants biomass
the energy from npp is also transfered to the next trophic level by consumers eg herbivours
how is 50 %GPP lost
through repsiration and lost to the enviroemnt as heat energy
why is not the energy in the consumers food transfered to the next trophic level ?
90% of the chemical energy stored in the consumers food is lost because not all parts of the plants are consumed eg the roots
it is also because some parts of plant matter are indigestable; so the food is egested and excreted so the energy si lost to the enviroment
energy is also lost through repiration , excretion or urine
how do we calculate the consumers net production
n= i - (f+r)
net production equals equals ingested food minus feaces plsu respitory loss
how do we calculate the efficency of energy transfer from trophic level to the next
we divide the amount from the higher trophic level by the amount from the lower trophic level and multiply by one hundred
as you move up the food chain, why does energy transfer become more efficent
because most parts of plant matter are indigestibale which means energy is lost to the enviremonet through exceretion. than consumers
what do food webs and food chains show
shows the energy transfer through an ecosystem
whats a trophic level
trophic levels describe the position of an organism in a food chain, web
why do farming practices aim to increase the amount of available energy that is available for human consumption of crops (npp) and live stock(np)
farming practices want to maximise the amount of chemicla energy stored as biomass for human consumption, increasing their net production ; this means increasing the NPP of plants and the Np of livestock
This can be acheieved in two ways;
1) energy transfer can be lost through other organisms such as pests
energy can be saved, simplifying food chains eg use of pesticides
2) by reducing raspatory loss eg pens etc
