About CO2

[iRock]

I know 1 mature tree can store 48 lbs CO2 per year and give 260 lbs O2 per tree per year . So exactly how much CO2 1 tree use per year for photosynthesis and storing process or just only 48 lbs ?

I know grassland absorb 2400 – 3600 lbs CO2 per acre per year and create half kilogram O2 per 1 square foot per day . So exactly how much CO2 grassland use per year for photosynthesis and storing process ?

[EdEarl]

Were do you get those numbers for CO2 and O2 for trees and grass?

[John Cuthber]

The numbers don't tally.

If you take in 48 pounds of CO2 you can't magically turn that into 260Lbs of O2.

Where would the extra 200 odd pounds come from?

[overtone]

 

 

I know 1 mature tree can store 48 lbs CO2 per year and give 260 lbs O2 per tree per year

Trees don't store CO₂ , they store the carbon and (bottom line books) release the the O₂ (when photosynthesizing normally, with respiration damped or swamped). There's twice as many O atoms as C per molecule, and they are each heavier than a C atom. That may clarify your accounting there.

 

The amount of carbon a tree removes from the air varies enormously by species, stage of life, and growing conditions. Also, mode of death - only the carbon sequestered from the atmosphere after death has been actually removed (buried leaves, etc, count, partially. Burned wood does not, completely).

[John Cuthber]

Each molecule of CO2 weighs 44 times as much as a hydrogen atom (it's an odd unit of weight, but it's used a lot in chemistry).

 

Each carbon atom has a mass of 12 on that scale, and each oxygen has a mass of 16.

So 44 grams of CO2 contains 12 grams of carbon and 32 grams of oxygen.

The tree takes that in and splits the C from the O2, it releases the O2 to the air and combines the C with H2O to make (mainly) cellulose.

 

So a tree that takes in 48 lbs of CO2 will produce 48/44 *32 i.e about 34.9 lbs of oxygen.

 

So, as I said, there's about 200 Lbs to still account for (225.1 to be a bit more exact).

 

Where does it come from?