O2, CO2 and trees?

stephen fitzgerald stephenf at netspace.net.au
Sun Nov 19 04:24:54 EST 1995

cleanusa at ix.netcom.com (Henri D Harness ) wrote:
>In <48bqob$bl0 at mark.ucdavis.edu> ez054530 at ucdavis.edu (Thomas Confal)
>>In article <488msj$fju at ixnews7.ix.netcom.com>, cleanusa at ix.netcom.com
>(Henri D Harness ) says:
>>>OK, I know trees come in all shapes and sizes, but I'm looking for a
>>>fair general answer or a range to the following related questions:
>>>1.  How much oxygen does the average tree produce?
>>>2.  How much carbon dioxide does the average tree produce?
>>>The sad fact is, I've read these numbers somewhere, but for the life
>>>of me, I don't recall.  I'd much appreciate answers and, if possible,
>>>sources.  It's become one of those questions that incessantly pesters
>>>the mind.
>>I'm not sure you will find an exact answer for all trees. The amount
>>of production depends on severl things: The type of tree (pine vs
>>broad leaf), the amount of stomatas present, the amount of light the
>>leaves are recieving for photosynthasis, if the tree is growing with
>>out stress for best growth, etc. If  you do find a number, see if its
>>for a given set of paramiters.
>    The numbers I remember reading applied to broadleaf/deciduous
>trees and there was reference to an average period of sunlight.
>Regardless, any figures on O2 production/CO2 consumption would
>be appreciated.  I thought that, if nothing else, I would find
>such figures for an oak or a maple, but my search for answers
>has been bootless to date.
>    I asked some friends and acquaintances in related fields --
>including a forester -- almost all said that they had read some
>such relevant figures somewhere, that the numbers were probably
>there in their offices, but that they were darned if they could
>find them.
>    And that's just it.  I was sure I had a paper in my office
>that compared O2 production/CO2 consumption estimates of different
>trees and that _approximated_ the global O2 production/CO2 consumption
>of trees, but I can't find it.  And now that any real need for an
>answer has long passed, I'm still searching for answers, wondering
>where the blip I read such figures or if I dreamed I read it.

Sorry Henry but I can't answer your question either but I can appreciate 
the sort of information you are after - just a "ball-park" figure right?
(or as you said "a fair general answer". I know I have read figures 
somewhere too but cannot find them. There is however some usefull 
information in 'Arboriculture' by Richard W. Harris p.6. Harris reckons 
that photosynthesis in the oceans accounts for 70 to 90% of the worlds 
total oxygen and that the contribution by land plants is probably 
insignificant. He also has some figures regarding how many trees it takes 
to negate pollutants such as sulphur dioxide etc. 
I don't know if this is any help but it is interesting anyway.

good luck in your quest.


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