EE22

Question 1

What molecules did the early atmosphere contain?

Answer 1

CH4
CO2
NH3
H2
N2
H2O
* prebiotic molecular soup of aa purines and pyrimidines develop

Question 2

What is the basis for life?

Answer 2

carbon

Question 3

What are carbon sources and sinks?

Answer 3

sources
-respiration
-deforestation
-decompisition
-burning fossil fuels
sink
-biomass
-sediments

Question 4

What kind of carbon exchange is biomass at equilibrium?

Answer 4

neither a sink or source
fixation balanced by respiration
biomass couldnt buffer changes in atmospheric C02

Question 5

What are carbon pools?

Answer 5

solids - rocks and sediments
gasses - atmosphere
400ppm now 
265ppm pre industrial revolution
water 
clathrates

Question 6

what is a clathrate?

Answer 6

solids composed of water molecules forming rigid lattic cages
each cage contains 1 molecule of methane
water crystallises into small isometric crystallorgraphic system rather than hexagonal system of normal ice

Question 7

what is the clathrate gun hypothesis?

Answer 7

energy gun loaded as clathrates build up in cold periods
fun fired cause rapid greenhouse warming
occurs on different time scales ad magnitudes
produce well documented sawtooth pattern of temperature change

Question 8

what is alochthonos?

Answer 8

denoting sediment or rock that originated at distance from its present position

Question 9

what is autochthonous?

Answer 9

deposits formed in current position

Question 10

what human activities cause carbon flux?

Answer 10

Burning
deforestation
CFCs- ozone depleteting
modern agriculture

Question 11

what are the consequences of increased co2?

Answer 11

immediate increase in photosynthesis of C3 plants, often dissapears after long exposure- suggests homeostasis
increased biomass and fruit production
34% water saving for 2X Co2
Root shoots ratio increases
N-fixders benefit more than other plants

Question 12

In which ecosystems might photosynthesis be co2 limited?

Answer 12

C3>C4
increased Co2 is increased water use efficiency
-reduced food quality for herbivores

Question 13

What is net CO2 assimilation rate at higher termperatures?

Answer 13

higher at higher temps

Question 14

what are fluxes?

Answer 14

processes that transfer from one pool to another

Question 15

What is residence time?

Answer 15

looks like a backwards Tau

av. amount of time a particle spends in a particular system

Question 16

What affect is increasing CO2 levels having on some South African biomass plots?

Answer 16

change in total biomass from 59 plots across SA
show general increase in biomass
- most parsimonious explanation is increase in plant resource availability Co2 increase NPP
mortality is increasing but lagging behind accelerated growth
increase atmos Co2 = fertilizing remote tropical untouched forest
causing carbon sink

Question 17

C sink =

Answer 17

change in NPP x residence time (J)
(J) = mass/flux
J= yrs