Name: Catherine
Status: student
Grade: other
Location: Outside U.S.
Country: New Zealand
Date: Spring 2010
Question:
What ways are available to measure carbon content that is
held within trees? i already have remote sensing and measure the
diameter etc of the tree but need to know a few other ways
Anthony Brach, PhD
Missouri Botanical Garden
You will have to check the reliability of the following method, using
refined charcoal as a calibrate. Burn the sample in an excess of
Oxygen, so that all the carbon is burned to CO2. Then add an excess of
Ca(Cl)2. Keep the system closed throughout the procedure, because
water soluble calcium salts tend to absorb CO2 from the atmosphere.
The Ca(Cl)2 reacts with the CO2 forming Ca(CO3) which is insoluble in
water. Some hints: Run the combustion in a weighed flask so that you
don't have to scrape the Ca(CO3) from the flask. That transfer could
be a major source of error. You want to avoid transfers as much as
possible. Make sure to rinse the Ca(CO3) several times with water to
be sure all the Ca(Cl)2 is washed away.
There are variations on this general method, depending upon the
desired accuracy. For example, if you just burn the wood and assume
that the non-combustible ash is negligible, you get a direct measure
of the carbon present. Yet another variation is to weigh the tare,
then ash + tare to obtain a measure of the non-combustible ash.
If you search the term "carbon analysis wood" you will find that the
accurate analysis for carbon in wood is not an easy analysis.
NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.
