After 10 years in the ground a newly planted tree will have
produced perhaps 2000 leaves. It will have a weak root system
which is not storing any calculable amount of carbon.
As the leaf area of a tree increases, its potential to photosynthesise
and therefore capture and store carbon, increases. Broad-scale
estimations of the leaf area index of tree species or even
forested areas are commonly used to indicate their potential
to capture carbon.
Cutting trees down over
a pre-determined period of time is a form of silviculture
known in the United Kingdom as Coppicing.
“Because of having substantial
amount of carbon storage, coppice stands can considerably
reduce the negative effects of greenhouse gases. Therefore,
serious attempts should be made to keep, preserve and enrich
these natural resources which play a very vital role in
the terrestrial ecosystems” (A. Khademi, Scientific
Member of Islamic Azad University, Malayer Branch, Iran,
2009).
Coppice management encourages trees to produce a mass of
leaves and optimises their ability to capture light.
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This picture was taken in July 2010. It shows the regrowth
from the stump of an alder tree (Alnus glutinosa)
that was cut down in March 2010. The regrowth from the cut
stump is more than 60inches in height and there are more than
50 separate stems, each supporting about 20 leaves.
After 10 years a coppiced alder will have produced 10,000
leaves. It will have a strong root system which has been storing
carbon for anywhere from 10 – 100 years before cutting
– perhaps longer when coppice/pollard is cut in very
old woodland - and in the time that it takes the planted tree
to mature, it will have provided ten harvest’s worth
of usable material.
The wood that was cut from this stump was used to grow mushrooms,
which go to make up a range of organic animal feed supplements.
Theoretically, this stump could be cut every ten years to
provide a home for the mushrooms, and when the mushrooms have
been harvested the wood is allowed to rot down back into the
soil.
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People
have been cutting trees down and allowing them to regrow from
the stump since the Neolithic.
It is a practice which supports woodland diversity, rather
than prevents it,
and potentially, it can prolong the life of a tree by several
hundred years. |
