Re: GAS-L: Woodland Management Info Sought

[Andrew Heggie <andrew.heggie@dtn.ntl.com>]

On Wed, 24 Jan 2001 08:20:42 +1100, Peter wrote:

>Hello Ken,
>
>Sounds good.  Just a few quick comments on sustainable management of
>woodland/forest.  I am not familiar with the growth patterns/species in the
>area you describe so these will be general.

One thing to consider is that this is SE England, a landscape with a
history of (good and bad) management going back 4000years. The
woodland is a small part of the land area and is fragmented, such that
many species only exist because of certain previous management
practises. Because of the nature of woodland and how it was treated
much wood was run in two storeys, standards and underwood or pure
coppice. Whilst MAI and Current annual increment lines crossing do
maximise production they do not necessarily concur with appropriate
price size relationships. Further as the area is an extremely rich
part of the global economy it has often survived for reasons other
than timber production as we can and do import a *very* large
proportion of our wood fibre needs. That woodfibre we produce at home
is produced on the large scale softwood forestry plantations in
Anglia, the borders Scotland and Wales, where Peter's recipe is
followed.

An effect of the " neglect" for forest management purposes is that
much of the woodland is becoming moribund, it simply will not react to
thinning and the increment has tailed off. With the loss of large
scale agriculture the vermin population is rampant, this means
managing traditional coppice can lead to loss of stools if they are
not guarded, so one has to think carefully when considering clear cuts
or cants.

>
>
>It is very important in any harvesting system that at least the bark, small
>limbs and leaves be returned to the site.  These contain the bulk of the
>sites nutrients contained within the forest.

Oddly enough one of the features of coppice in this area is that total
biomass removal was practised, this has lead to a low surface
fertility that has suited certain gap loving species (especially the
shade evader bluebell), which are globally rare. In any less benign
climate or nutrient deficient soil it would have been a recipe for
disaster.
>
>Analogue forestry attempts to mimick as close as possible the natural system
>and harvest mainly consists of salvage of naturally fallen trees and
>selective thinning, producing small "light wells" in the forest canopy which
>encourage young trees to grow.  To be effective it requires a high degree of
>forest knowledge (dead trees are often very important for habitat) and a
>strong back since it does not rely on machinery to any great extent
>(operating machinery on this basis tends to do more harm to the system
>because you are all over the forest picking small areas).

This sounds like what is referred to as continuous cover forestry
here. This is the sort of approach I have worked on for a number of
years. We do use machinery but instead of hot loh=gging we attempt to
mimic the practice of winter felling and summer extraction which our
forebears had no option but to do.
-

>Behalf Of Ken Boak
>  Sent: Tuesday, January 23, 2001 9:46 AM
>  To: gasification@crest.org
>  Subject: GAS-L: Woodland Management Info Sought
>
>
>  Tom and Gasification List,
>
>  An opportunity exists to have access to waste wood from a 40 acre wood on
>a Victorian estate in the south of England. The start of this woodland area
>is just 250 yards from my front door.
>
>  I need some hard and fast facts about woodland management from a
>sustainable fuel source point of view.  The trees are predominately
>deciduous and in the region of 50 years plus old.

First look to the legal requirements of felling licences.
>
>  As a first estimate, I would say that there is 1000 tonnes of wood lying
>around the 250 acre estate, as a result of 30 years of  under-management.
>
>  There are numerous buildings on the estate which would benefit from a wood
>fired heat system. These include converted stables, green houses and
>workshop buildings.

I am happy to talk about this on a practical level, self consumption
of wood for local heating stands on its own now. Typically with
harvesting costs in the GBP12-15 area, pulp prices of <GBP 18 on a
smaller part of the size assortment then we can compete.

>  I am currently thinking of a 5kW Stirling engine (URL below) and gasifier
>which could handle perhaps 200lbs of wood per day for six months (winter)
>per year. Charcoal would be either used locally - blacksmith or sold during
>summer as barbeque fuel.

One day! We can do most of this now, I think the sterling bit is out
of economic reach at present. I only know of one blacksmith using
charcoal, most gets sold into the barbecue market. We could hit the
road with a clean charcoal maker and co heat the buildings in fairly
short order.
>
>  http://www.stirling-tech.com/stirling/total.htm
>
>  Power generated would be used to recharge a small fleet of electric access
>vehicles  (golf buggies) used to allow elderly and disabled to acces areas
>of the estate.

I would love to play at this, my feeling it is most landowners will
not dig this deep into their pockets.
>
>  Does anyone have experience of a similar size of woodland?

About 80years between the three of us! Mostly on the Lower greensand
and weald.
AJH

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