How much carbon is absorbed ( / annum / ha) in northern forests?

Question

I am interested to know the quantity of carbon sequestered annually per hectare in northern (Canada, Norway, Sweden, Finland, etc) forests (i.e spruce and pine forests). If the info is available for the carbon absorption at different ages of the forest then that would be great to see. I am specifically talking of plantation forests rather than original growth areas.

I would be looking for sources for your info too.

Thanks very much for your help, all I can find is info on Australian forests!

Kind regards and best wishes
Resolution

Answer 1

I would say you should research how many cubic feet of wood mass grows in a particular area per year. The gov, agricuture site should have this. Then research how much carbon is in a cubic foot of pine, or whatever tree grows there.

Remember bark and branchs and leaves will have carbon too and that will be the hardest parrt. You might have to give that an educated guess. Say maybe 25% more.

Answer 2

≈8800kg

Explanation
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Based on some quick mathematics as I don't have any figures to hand...

Typical height of a mature spruce or pine = 40 metres
Typical girth = 800mm
As near as damn it all the mass is in the trunk (trees planted for commericial purposes have almost no branches)
Volume of a typical tree = just over 2 million cm³
Typical density = 0.65g/cm³
Typical mass of one tree = 1300kg
67% of a tree is carbon
Carbon content = 887kg per tree
Growing time typically 40 years
Average carbon sequestration per tree per year = 22kg (which sounds about right).
Recommended coniferous forest planting = 400 trees per hectare.
Therefore one hactare of 400 trees sequesters an average of 8800kg of CO2 per year (best say ± 50%)

If a precise figure is important to you then let me know, I can get the info but it will be a couple of weeks as the relevant expert that I'd need to speak to is on holiday.

Other Info
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The countries that you've mentioned are generally cold countries and the amount of solar radiation absorbed by trees in cold climates can more than offset the amount of CO2 the trees sequester. This is especially true in areas where snow often lies on the ground.

In commercial forests the trees are planted as close together as possible in order that no sunlight penetrates the canopy so the trees only ever grow upwards (apart from those around the edges). In this respect only the upper part of the trees will be exposed to sunlight so the amout of solar radiation absorbed will be a lot less than in a naturally occuring forest.

If there's snow on the ground almost all solar radiation is reflected back into space but if there's tree cover then heat is absorbed and subsequently radiated back out as thermal radiation - the type that gets trapped by greenhouse gases.