CO2 Absorption by banyan tree

Wow! That's a real fine research project you've taken up!

I'm not a biologist but, if given this task, I would conduct a series of experiments using a CO₂ meter, a low flow meter and a contraption that would allow me to fasten a glass tube on a leaf where I can inject CO₂ at atmospheric pressure. Then I'll measure the flow of CO₂. You make sure that the tube and leaf are in contact and that there are no leaks. I hope you don't damage the leaf if you do it this way.

You do this on several leaves to get an average figure (must do this with the leaf still connected to the tree). You then measure the average area of each leaf, and estimate the number of leaves on the tree.

This is an engineer's approach to your problem and others may already have a tried and true method.

Hum,mm I wonder if you can measure the oxygen content in a closed environment, to be able to detect this rate of photosynthesis ? I guess it would have to include a green house type of enclosure, for artificial lighting would give false truths.

Any apparatus will change the natural working of the tree.

What about estimating the weight/volume gain per time period and derive at a fair assumption of the CO2 absorbed. The CO2 should be proportional to the weight/volume.

Yeah man, now that's an answer ! I'm always looking at a hard way to go instead of seeing the simple ways.

Once you see the banyan in Calcutta (the largest one in the world), you will give up estimates of its volume, mass, etc.

I see your problem ! tee hee. I wonder if this could be achieved in it's primary state ?

I'd like to see what the oxygen emissions are like ?

Are you saying it's so large at cannot be walked around given enough time? Or paced of between "trunks"? Or its average or range of height reckoned by "field techniques"? Or that a sample grid or grids cannot be laid out amount its members? Or that a sample of trunk diameters cannot be measured. Or a count of trunks cannot be made? Or that there is no botanical records to be had about the tree?

Or that you seek only an easy way to go about finding what you need? Scientific inquiry sometimes takes long term commitment and patience. Perhaps the effort that would be required both to learn how to measure the tree, and to go about measuring it (either directly or be deduction), is not really worth any benefit to be gained in estimating its metabolic uptake of CO²?

First you need to decide some parameters. Asking how much CO² inspiration is like asking how much oxygen do you absorb. In what period of time? Seconds? days? decades? Life of tree until death? Etc? In what season of year? At what temperature? At what sun exposure, or non exposure? Where in the fruiting cycle? The list could go on and on. You will probably get further by determining the mass of the tree at any point, A, in time; then again at fixed intervals later on--this could go on for many years. Having determined a rate of growth (net mass increase over time, including mass of fruit, and mass losses) you should then be able to estimate (the more samples the more accurately) the actual amount of CO² actually used. Understand that these determinations will involve gaining a quantitative understanding of the molecular biology of plant metabolism--and that the starting point would be best at the cellular biology level--those disciplines are where you will find the answers you need to set up your investigation. Realistically, the problem you have posed is one which falls outside the "engineering" sphere, whether it is approached as a scientific investigation, or as an amateur's hobby project.

Sorry if this seems discouraging; but hate to see anyone "bark up the wrong tree" both unnecessarily and unfruitfully!

I am wondering the purpose of this exercise. Is this a school project or are you a botanist or environmentalist.

I thought it was something like a big banana.

Your forestry department must already have a good estimate of the volume and mass of the tree. Ask them.

A good approximation may be obtained by measuring the increase in the size of the trunk in a few places.

You may have to use a seedling to correlate your finding.

Another method may be to use the infrared band of satellite images to estimate the photosynthesis activity. Can you spot the tree on Google.earth?

You will have to improvise.