Consider a stock of atmospheric CO2 over a hypothetical forest ecosystem in whic
ID: 113431 • Letter: C
Question
Consider a stock of atmospheric CO2 over a hypothetical forest ecosystem in which net primary productivity (NPP, or the net rate of uptake and conversion of C-CO2, expressed as kg C-CO2 per month) is zero from January to May and then ramps up rapidly to 6 kg C-CO2 /month until October, or month 10). Respiration is effectively zero in this hypothetical ecosystem. If the initial atmospheric C-CO2 level is 40 kg C, what is the level of the atmospheric C-CO2 stock, in kg C-CO2, at the beginning of month 5 (May)?
by month 10?
by month 12?
can someone please help me out and explain, I do not understand
Explanation / Answer
The level of the atmospheric C-CO2 stock at the beginning of month 5 (May) will be 40 kg C-CO2 beacuse the NPP was zero from the month of January to May. Also the respiration is effectively zero in this hypothetical ecosystem so neither the level of C-CO2 will fall nor will it rise.
By the month 10 that is October it will be = 40 kg C-CO2 (initial atmospheric C-CO2 level) + 6 kg C-CO2 /month X 5 months (June to October; since the NPP ramps up from June to October at 6 kg C-CO2 /month)
=40+30 =70 kg C-CO2
By the month 12 that is December it will be 70 kg C-CO2 because there is no NPP in the months of November & December.