Carbon and land-atmosphere interactions

Question 1

How do C emissions change with changing water table level

Answer 1

POP

When water high then green tree phots and takes down co2. Gives water back through evapotranspiration

When water low, drier,, drought. Carbon source not sink. Massive heat flux

Heat wave of 2003, loads of carbon was given out. There is lots fo stochasticity in the system.

Question 2

Temporal variations in land characteristics

Answer 2

Albedo varies throughout the year

Question 3

Autotrophic

Answer 3

What green parts respire

Question 4

Gross primary productivity

Answer 4

Total c fixed by plants through phot.

Question 5

Net primary productivity

Answer 5

GPP - autotrophic respiration

Question 6

Net ecosystem exchange/ production

Answer 6

NPP - heterotrophic respiration

Question 7

Net biome exchange/ production

Answer 7

Nee/NEP - losses due to disturbances (fire, soil tillage etc)

Question 8

Heterotrophic

Answer 8

All bits that aren’t green respire

Question 9

How much C that plants put into roots leaks out into the rhizosphere

Answer 9

40-60%

Used by all sorts f biota as C source. Often help plant mineralise N

Question 10

Measuring co2 experiment

Answer 10

can measure with chambers and branch bags

Often rather than v small info we need large scale info so have to employ micrometerological techniques

• scaffold tower- has solar panels for power supply in remote areas and records radiation (long and short), sunshine duration, wind speed, infrared gas analyser (monitoring fluxes in co2 and h2o)
• oceans research - sometimes merchant ships fitted with gas sampling and meteorological kit
• can look at methane too, Need unable diode laser instead of IRGA?. Can help create model constraints
• high complexity bc spatial heterogeneity, feedbacks and interactions