Global primary production- FI Woodward

Question 1

where is the primary CO2 source released from humans from?

Answer 1

from fossil carbon fixed by prehistoric photosynthesis

Question 2

what do natural systems act as?

Answer 2

sink for CO2 human emissions

Question 3

what is gross primary production (GPP)?

Answer 3

• rate of production of chemical energy
• net photosynthesis
• photosynthetic conversion of solar radiation to produce ATP and NADPH (CO2 fixation)
• chemical energy in metabolites used to synthesise plant biomass from CO2 and H2O

Question 4

what does primary production provide?

Answer 4

energy source and substrates for major food chains

Question 5

over a year what happens to the GPP?

Answer 5

1/2 fixed into biomass

1/2 lost by respiratory processes

Question 6

what is net primary production (NPP)? (2 equations)

Answer 6

= GPP - autotrophic respiration
( often measured by difference in biomass sampled 1 year apart)
= photosynthetic biomass X growth efficiency X light

Question 7

what is net ecosystem production (NEP)?

Answer 7

= NPP - heterotrophic respiration

Question 8

what is net biome production (NBP)?

Answer 8

= NEP - losses through disturbance

Question 9

how do you work out biomass?

Answer 9

= total ( NPP - losses through litter fall)

Question 10

why may NPP not be estimated for correctly?

Answer 10

• some biomass is lost as dead litter fall
• may miss unaccounted losses of new biomass
• sampling errors

Question 11

what is day photosynthetic CO2 uptake balanced by?

Answer 11

night CO2 release by respiration

Question 12

what is photosynthetic biomass made up of?

Answer 12

green leaves/chlorophyll

Question 13

what is growth efficiency a measure of?

Answer 13

of conversion of solar radiation to carbon units of NPP

Question 14

what can quantify critical components of NPP model?

Answer 14

measurements by satellites of reflected radiation from earths surface

Question 15

what is used to help you calculate amount of photosynthetically active radiation?

Answer 15

reflected radiation at different wavebands

Question 16

how is density of leaves calculated?

Answer 16

measurements of reflected radiation in infra red/ red zone

Question 17

how is phytoplankton chlorophyll and biomass in oceans calculated?

Answer 17

different wavebands of reflected blue light

Question 18

what are the 2 roughly equal biospheres?

Answer 18

terrestrial and oceanic

Question 19

where is there high NPP?

Answer 19

• where coastal upwelling of nutrients

- rainforests

Question 20

which nutrients result in low productivity for deep oceans?

Answer 20

nitrogen, iron, phosphate

Question 21

what may reduce NPP?

Answer 21

seasonal variations of temp or precipitation

Question 22

for each 1c decrease in mean annual temp in Europe what is the effect on NPP?

Answer 22

reduced by 4%

Question 23

a) NPP of pacific = ….

b) NPP of S and arctic oceans = ……

Answer 23

a) = NPP tropical rainforests

b) = NPP boreal forset

Question 24

why is there more loss of C on and and what % of human emissions does this account for?

Answer 24

due to soil erosion and fires

20-30%

Question 25

what can a ‘biological pump’ maintain?

Answer 25

high conc of dissolved C in ocean

Question 26

what part of the ocean has high solubility?

Answer 26

cold waters at high latitudes

dense water sinks removing CO2 to depths

Question 27

in the ocean what is 1% of it and what is the other 99%?

Answer 27

1%: inorganic C

99%: bicarbonate and carbonate ions

Question 28

fill in the equation:

CO2 + H2O + ___ —> _____

Answer 28

CO3^2-

2HCO3-

Question 29

what is the decreases in NPP by biological pump correlated with?

Answer 29

increase in sea surface temp

Question 30

what decreases the effectiveness of solubility pump?

Answer 30

decreased carbonate ion conc and decreased ph

Question 31

C accumulation in atmosphere: atmospheric CO2 conc: global warming
number comparison?

Answer 31

200: 100: 1

Question 32

what was discussed to reduce C emissions?

Answer 32

planting trees

Question 33

what could total deforestation lead to a global warming of?

Answer 33

2c

Question 34

on what scale can global climate change for the better?

Answer 34

internationally

Question 35

what % of anthropogenic emissions do oceanic and terrestrial sinks sequester?

Answer 35

60%

Question 36

what can increasing iron stimulate?

Answer 36

plantkon growth and C uptake

Question 37

what could terrestrial NPP be harvested to manufacture?

Answer 37

ethanol from sugar cane rather than using petrol

Question 38

why does use of sugar cane have a neutral effect of atmospheric CO2?

Answer 38

grows and sequesters C but C is releases again in car exhaust

Question 39

why is ethanol from sugar cane not C neutral?

Answer 39

costs for growing and harvesting it

Question 40

what % of energy content of petrol does sugar cane have?

Answer 40

65%

Question 41

what is likely to happen to natural sinks for CO2 emissions?

Answer 41

slow

Question 42

what would converting UK land for ethanol production impact?

Answer 42

area for food crops, species diversity, natural vegetation

Question 43

what does reduced primary production of terrestrial biosphere result in?

Answer 43

warmer and drier conditions- drought more likely

Question 44

warming oceans leads to stratification what does this lead to?

Answer 44

reduced nutrient supply for phytoplankton and reduced solubility of CO2 in warm waters so decreased primary production

Question 45

what should be done to improve emission rates/climate change?

Answer 45

reduce emissions from CO2 sources and move away from energy systems based on carbon