carbon fixation

what is 'carbon fixation' ? is it consumption of co2 by trees ?

Essentially yes.
simplistic explanation:
Co2 is converted to carbon stored as lignite (wood fibre) in trees.

there is a mathematical model to estimate the amount of carbon fixed in a certain sized tree. i'll see if i can find it.

I understand the language, Tintin, but I don't understand the meaning. This is going to require someone better versed in the sciences than this ole boy.

Why do threads like this keep getting tagged "politics?" There's no political content here. Is this a glitch in the system? Is there some member who thinks it's funny to tag threads as "politics?"

I've been doing that to try to keep you from "advising" students on language issues, Setanta.

glad to know this 'Co2 is converted to carbon stored as lignite (wood fibre) in trees' .


So, can we say every living tree has some carbon in it ? say.. a mango tree , or a banana tree ...do they also have some amount of carbon in it ?

the word used here 'carbon fixation' ......'fixation' means something is fixed ...right ? what is fixed here ? why its fixed ?

I'm sure you know all these ...can you please elaborate a little please.

Thanks for your time.

all trees have some amount of carbon fixed into their structure. different trees have differing amounts. banna trees would have less carbon stored than, for example, a conifer or eucalypt. this is due to the bannana trees rapid growth and cell structure. generally speaking we could say that trees that grow slowly have more stored carbon than trees that grow rapidly.
of course the size of the tree makes a difference as well.
in addition the parts of the tree that are underground are also stored carbon. scientific measurements of Australian eucalypts show that aproximatly 30% of the carbon stored in a tree is underground in the root structure. if we consider the tree as a whole; leaves, branches, trunk and root system, 70% of the stored carbon is above ground in the leaves branches and trunk and 30% is below ground in the root structure.


if it is easier to understand try substituting the word "stored" in place of "fixed".

Each tiny cell in the trees leaves branches trunk and roots is made up of cellulose water and lignite and other chemical and mineral componants. all these componantss contain a certain amount of carbon as well as other things so effectivly the co2 had been "fixed" or "stored" as carbon in the cell structure instead of being free to float around in the air as carbon dioxide (CO2).
If you were able to dry all the water out of a piece wood it would be mostly carbon.

Do you know the term charcoal? charcoal is almost all carbon.

This picture is wood that has had all the water dried out of it.

fixed can have several meanings in english and this is why context becomes important.

My car broke down so i took it to a mechanic to have it fixed.
'fixed" means repaired.

the shelf was fixed to the wall with screws.
"fixed" here means held together.

the carbon dioxide is fixed within the the tree
"fixed" means converted to a solid and stored.

beautiful explanation ... lots of information . i enjoyed it .

thanks a lot.

Before all the kerfluffle about "Human induced global warming" and "carbon sequestration or fixation", this entire process was known as "primary production of biomass" since thats how plants grow . They add on cell and tissue structure primarily from atmospheric carbon dioxide and silica through the vascular system.

I agree with Tintin, DP has done a marvelous job of explaining these processes.

Dadpad did do that, no bout adoubt it, but no one has explained this,

Increasing light duration may not increase the rate of carbon fixation, but the total amount of carbon fixed by photosynthesis will increase due to
increased light exposure.

Could you shed any light on this apparent contradiction, DP, FM? If the author is saying increasing light duration in and of itself doesn't increase the rate of carbon fixation, and that seems reasonable, why was 'may' chosen?

Is this a 'may' of "allowing that ..."?

The key phrase is "rate of fixation". More properly it should say "rate of fixation per hour of sunlight. This rate of fixation could be expressed as X cubic centimeters per hour of sunlight. If hours of sunlght could be extended, more wood would (deliberate use of homophone) be layed down each day but the rate of fixation would not change.
Rate of fixation is governed primarily by genetics then water and nutrient availability and crown size (total leaf area). Many other factors such as soil type, wind predator damage also impact.

Another interesting fact is that a small dense slow growing hardwood may actually contain more stored carbon than a larger fast growing softwood because of the cell size and retained water.

Fast growing tree types like bananna or pawlonia have a large cell structure which, reletively speaking, contain a larger amount of water and less carbon than a denser hardwood.

Thats partly why certain types of wood are more valued for firewood or building material.

Then we get on to cell shapes and alignment, heartwood versus sapwood versus cambium and bark also latewood (winter) versus early wood spring . Whole nother story.

I have absolutely no business being up this late . . .

Once again, thanks to DP for his posts. I have learned a great deal, and about a subject in which i am genuinely interested.

re there any trees with a cell lattice that incorporate silica, (Like the many grasses or bamboo?) I woulda thought that stuff like ebony or bubinga (sp?) would be loaded with silica.

I had one of my older pawlonias(20 yars old) cut down and lumbered out for me. I did not realize that every steenking branch has like a central hole in it. SO I saved a bunch of strait 2" wide hunks to make some flutes when I get the notion. ALL I need is some idea what a flute looks like inside.

didgeridoo?



Dont know sorry. mineral elements would need to be in a water soluable form and even then the larger elements like salt get filtered out. It'd be hell on a chainsaw if there was.

Thats why bamboo is so hard and yet light. Several tall prairie grasses in the US "Great Plains" are silica based and are almost inedible to the wild cattle. I thought that there may be a bush or tree with similar makeup.

The cedar that grows around here (high desert) will ruin a chainsaw blade, from what I hear. I'm not at all sure the silica is actually within the cell structure. It may just be present as inclusions, for all I know.

That's hearsay. I got too many smarts to be messing around with chainsaws.

Silica is often incorporated within cell structures of grasses and ferns. It comes from a solution of organic silicic acids which are present at about 3 to 8& of the soil chemistry. Plants take it up in the liquid form and then polymers form as crystal lattices that give certain grasses and ferns a scratchy surface. (The Chinese often used bamboo as an abrasive)