Calculating the carbon consumption of woodlands

[Tony Croft aka hamadryad]

Spagnum moss bogs lock far more carbon, the carbon sequestered in the soils is a much bigger part of the picture in this global crisis.

 

with 80% of forest eco system diversity revolving on a saprobic lifestyle what use is a young wood planted on a brown field site? very little till its got 300years into its cycle.

 

but we should not discourage re planting new forests!

[D Mc]

... the carbon sequestered in the soils is a much bigger part of the picture in this global crisis...but we should not discourage re planting new forests!

 

Totally agree. This article might give a little more insight, even though ag- based.

 

Glomalin: Hiding Place for a Third of the World's Stored Soil Carbon

 

We tend to think of our forests' ability to sequester carbon relative to wood volume when in reality it is so much more.

 

It still bothers me that even in advanced studies by these scientists, that bring to light intracacies within the soil that are part of the necessities of life, their focus still drifts towards isolation and patentability of such substances for financial gain. Much of the micro/fungal/bacterial-intensive studies of the last few decades have been focused in this manner.

 

Trying to make a better system when a perfect one already exists.

 

Dave

[Charlieh]

this will be interesting, i have worked on monitoring carbon on moorland but other than knowing it locks up the carbon in larger quantities and for longer than trees, i must admit this should be interesting to see if we could get a more academic perspective on the topic,

 

here is some of the moorland stuff i helped with, http://moorsforthefuture.org.uk/mftf/downloads/publications/MFF_researchnote12_carbonflux.pdf

if you get really stuck someone like Fred Worrall at Durham uni may be able to give you some info or point you in the right direction

[Tony Croft aka hamadryad]

Totally agree. This article might give a little more insight, even though ag- based.

 

Glomalin: Hiding Place for a Third of the World's Stored Soil Carbon

 

We tend to think of our forests' ability to sequester carbon relative to wood volume when in reality it is so much more.

 

It still bothers me that even in advanced studies by these scientists, that bring to light intracacies within the soil that are part of the necessities of life, their focus still drifts towards isolation and patentability of such substances for financial gain. Much of the micro/fungal/bacterial-intensive studies of the last few decades have been focused in this manner.

 

Trying to make a better system when a perfect one already exists.

 

Dave

 

This is influenced 100% by corporate drive, research requires funding, and no corporation is going to fund a profitless research project, it is down to us, as hard as that is to buy our own tools, use our own time to "expose" the REAL goings on. I know of at least on High profile researcher that gave up research due to corporate "influence"

 

money rules the world, sad but true.

[Quickthorn]

Does any body know how you can estimate how much carbon a mixed broadleaf woodland consumes every year ?

 

A client has asked us to add it into a report, it doesnt have to be totally accurate, just a rough figure.

 

As always thanks in advance

 

If this helps, a typical yield class for a broadleaf wood would be 4-6, so the timber yield over a rotation would be between 4-6 cubic metres per hectare per year. You just need to find out how much carbon is in a cubic m. of green wood (half of it would be water, of course).

 

From practical experience, I've been helping to coppice 1 ha blocks of broadleaf on a 20 year rotation, and we get around 100 cubic m. from that.

 

The tree-shaped text forgets to mention that trees respire as well, and that gives off carbon dioxide.

[D Mc]

This is influenced 100% by corporate drive,

 

Understood. I am most disturbed that these brainiacs keep pulling individual components out and expecting them, by themselves, to fix things.

 

I am most heartened that the article referencing glomalin did not get much of a rise for the hopeful reason that this is old news. It does not seem to be in most areas.

 

Dave

[Albedo]

How to calculate the amount of CO2 sequestered in a tree per year

We at Trees for the Future estimate that our agroforestry trees, planted in tropical

climates, will sequester atmospheric carbon dioxide at an average of 50 pounds of carbon

dioxide per tree per year.

The rate of carbon sequestration depends on the growth characteristics of the tree species,

the conditions for growth where the tree is planted, and the density of the tree's wood. It

is greatest in the younger stages of tree growth, between 20 to 50 years.1 Further

complicating the issue is the fact that far less research has been done on tropical tree

species as compared to temperate tree species.

Nevertheless, we can roughly estimate the amount of CO2 sequestered in a given tree,

and if we divide by the tree’s age, get a yearly sequestration rate.

We got this process from two educational websites who had conceived it as a learning

activity for their students. 2 This is the process:

1. Determine the total (green) weight of the tree.

2. Determine the dry weight of the tree.

3. Determine the weight of carbon in the tree.

4. Determine the weight of carbon dioxide sequestered in the tree

5. Determine the weight of CO2 sequestered in the tree per year

Determine the total (green) weight of the tree

Based on tree species in the Southeast United States, the algorithm to calculate the weight

of a tree is: 3

W = Above-ground weight of the tree in pounds

D = Diameter of the trunk in inches

H = Height of the tree in feet

For trees with D < 11:

W = 0.25D2H

For trees with D >= 11:

W = 0.15D2H

Depending on the species, the coefficient (e.g. 0.25) could change, and the variables D2

and H could be raised to exponents just above or below 1. However, these two equations

could be seen as an “average” of all the species’ equations.

The root system weighs about 20% as much as the above-ground weight of the tree.

Therefore, to determine the total green weight of the tree, multiply the above-ground

weight of the tree by 120%.

Determine the dry weight of the tree

This is based on an extension publication from the University of Nebraska.4 This

publication has a table with average weights for one cord of wood for different temperate

tree species. Taking all species in the table into account, the average tree is 72.5% dry

matter and 27.5% moisture.

Therefore, to determine the dry weight of the tree, multiply the weight of the tree by

72.5%.

Determine the weight of carbon in the tree

The average carbon content is generally 50% of the tree’s total volume.5 Therefore, to

determine the weight of carbon in the tree, multiply the dry weight of the tree by 50%.

Determine the weight of carbon dioxide sequestered in the tree

CO2 is composed of one molecule of Carbon and 2 molecules of Oxygen.

The atomic weight of Carbon is 12.001115.

The atomic weight of Oxygen is 15.9994.

The weight of CO2 is C+2*O=43.999915.

The ratio of CO2 to C is 43.999915/12.001115=3.6663.

Therefore, to determine the weight of carbon dioxide sequestered in the tree, multiply the

weight of carbon in the tree by 3.6663.6

Determine the weight of CO2 sequestered in the tree per year

Divide the weight of carbon dioxide sequestered in the tree by the age of the tree. Et

voila!

EXAMPLES

Estimated growth rates and sizes of agroforestry trees were taken from the World

Agroforestry Centre’s “Agroforestree Database”7:

Let’s see how much a Calliandra calothyrsus might sequester in a year. A 10-year-old

Calliandra would probably grow about 15 feet tall with a trunk about 8 inches in

diameter. Therefore:

W = 0.25D2H = 0.25(82)(15) = 240 lbs. green weight above ground.

240 lbs. * 120% = 288 lbs. green weight (roots included)

288 lbs. * 72.5% = 208.8 lbs. dry weight

208.8 lbs. * 50% = 104.4 lbs. carbon

104.4 lbs * 3.6663 = 382.8 lbs. CO2 sequestered

382.8 lbs / 10 years = 38.3 lbs. CO2 sequestered per year

Or consider a 10-year-old Grevillia robusta, 45 feet tall with a trunk 6 inches in diameter.

Using the same calculations as above, the amount of CO2 sequestered would be 64.6 lbs.

per year.

Or a newly-planted Acacia angustissima, 2.5 years old, 15 feet tall with a trunk 3 inches

in diameter: 21.5 lbs. of CO2 sequestered per year.

Or an Albizzia lebbek, 15 years old, 30 feet tall, with a 12 inch trunk: 68.9 lbs. of CO2

sequestered per year.

Other methods

Another way to estimate the amount of CO2 sequestered by a tree in a year is to estimate

the amount sequestered in a hectare per year, and divide that amount by the number of

trees per hectare. Scanning around on the Internet, it seems that the number of trees per

hectare (in agroforestry and/or industrial plantations) ranges from under 500 to over

2,000.

According to Myers and Goreau, tropical tree plantations of pine and eucalyptus can

sequester an average of 10 tons of carbon per hectare per year. 8 Therefore, the

plantation can sequester an average of 20,000 lbs * 3.6663 = 73,326 lbs CO2/ha/year, or,

taking an average of 1,000 trees per hectare, 73.326 lbs CO2/tree/year.

Of course, we heavily discourage the planting of pine and/or eucalyptus in our

agroforestry systems. Our trees may not grow as fast or as straight as eucalyptus, but

they are not invasive, and they do not destroy the water table and the soil!

[Tony Croft aka hamadryad]

All trees produce chemical leach, and hydrocarbons, it isnt just pines and eucs!

 

Tanins from oaks for example.