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Author Topic: How much wooodland do I need?  (Read 21204 times)
thebrick
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« on: February 22, 2009, 09:05:38 PM »

How much woodland do I need in oak/ash to be fully sustainable in wood? I burn about 8m3 per year and at present buy and cut from my local commune in France.
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johnrae
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« Reply #1 on: February 22, 2009, 09:23:48 PM »

I don't know the numbers but oak is a long life tree and takes decades to get to a decent size.  Burning good oak is "criminal", almost as bad as burning hydrocarbons.  The way things are going, in a few decades we'll be needing oak for house and ship building.

Ash on the other hand is a quick growing copice wood and I'd guess that you'd need about 10 times as much area to grown the equivalent amount of firewood if you were burning oak.

I believe that there may be other faster growing, more intensive woods suitable for firing, such as willow.

Jack
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guydewdney
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« Reply #2 on: February 22, 2009, 09:29:03 PM »

My mrs worked it out as about 5 acres - just - to warm our house - which is a 4 / 5 bedroom mill.

Theres good oak, and bad oak - usless oak is the thinnings, and bent stuff. Free oak comes as pallets from my local face paint shop  Huh

I have also heard willow is carp - as its too high a water content
« Last Edit: February 22, 2009, 11:11:43 PM by guydewdney » Logged

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billi
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« Reply #3 on: February 22, 2009, 09:44:25 PM »

Oak seemed to me ; like Arcadia   a wide/spread tree in France (south)  and has  surely a good potential for burning , but who preserves these Forrest then ?  and the wild bore and the "cpe", sure thinning out makes sense
like the french Man Jean Pain did
I would consider to grow my own firewood /fuel as well

billi


« Last Edit: February 22, 2009, 10:02:21 PM by billi » Logged

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« Reply #4 on: February 22, 2009, 11:07:36 PM »

Is Oak not one of those things you plant for future generations not your own?
Surely its too slow growing to plant now and harvest anytime soon?



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Roy
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« Reply #5 on: February 22, 2009, 11:32:30 PM »

coppice willow is the best i think
type "the willow bank" into google for some ideas
or it can be pollarded
cut it every 5 years and get 4 inch logs?

i think it can be done in less than 5 acres???

laters
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lightfoot
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« Reply #6 on: February 23, 2009, 06:20:04 AM »

It will depend on species, local growing conditions and management etc, but in round figures, you could allow around a cord of firewood per acre (0.4 hectare), per year from a woodland. 

A cord of stacked logs is 4' x 4' x 8' or 128 cu/ft (3.6m3) of which allowing for air spaces, will be around 60% wood (~2m3) or around 1 to 1.5 tonnes of logs, depending on species and how well you stack it etc etc.

So depending on whether your requirement of 8m3 refers to stacked logs or solid wood etc, as a guide in round figures, you would need somewhere in the region of 1 to 2 hectares of woodland - an Ash or mixed coppice would be ideal.  Note: Oak can be very corrosive and may have a tendency to rot any plain steel/iron parts of your WBS/log boiler that it comes in contact with - if you must burn it, make sure it's well seasoned and mix it in with some other logs.


Hope that helps,

Lightfoot.


PS, For further info, you may find this handy.... http://handbooks.btcv.org.uk/handbooks/content/section/3767
« Last Edit: February 23, 2009, 07:01:52 AM by lightfoot » Logged

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briand
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« Reply #7 on: February 23, 2009, 03:30:00 PM »

If you are going to treat wood as a crop and harvest it you need to coppice rather than fell your wood. If you use hazel or willow you will be able to start coppicing after 7 to 10 years, and coppice each plant every 7 years or so. By coppicing a seventh of your trees each year you will always have some ready for next year
Not all species are happy being coppiced but hazel and willow are - but not the only ones
Their are lots of study reports on the web for instance-
http://www.coppice.org.uk/return.htm

Coppice in the heart of winter when the water content is already low, then split and stack somewhere warm and dry and it will be down to 12% moisture by the following winter. Dry willow burns just as well as dry ash - but wet willow won't burn. Moisture content in most woods on coppicing will be around 30%.

I expect there will be mains power stations running on hazel and willow within 20 years.

good luck
Brian


I expect you will need to allow an extra 30% of area to allow for the time to get up to full production - 10 years before first crop - unless you can buy some existing woodland
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Bill H
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« Reply #8 on: February 24, 2009, 06:50:41 AM »



I expect there will be mains power stations running on hazel and willow within 20 years.


Yes, they already started.

http://news.bbc.co.uk/1/hi/england/oxfordshire/6046774.stm

www.saxlund.co.uk/uploads///images/Plant%20Reports/Plant%20Report%20Didcot%202007%20V2.pdf

Bill
« Last Edit: February 24, 2009, 06:54:17 AM by Bill H » Logged

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« Reply #9 on: February 24, 2009, 09:36:47 AM »

Slough Trading Estate's power station,
(now owned by SSE) has been using wood and wood chip for a long time.

http://www.sloughheatandpower.co.uk/index.htm
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« Reply #10 on: February 24, 2009, 10:36:59 AM »

Given the space oak is not a bad choice as a fuel source.   An oak tree I planted at the last house is quite a large tree now after about 25 years.    Oak trees have an advantage that they allow grass to grow underneath even when they are large and are a good for attracting wildlife because they host a lot of insects.   I am going to cheat a bit and get some oak trees already growing.  They can be moved quite easily with tractor and tree spade.    There should be trees available in most places as thinnings from commercial forests.    If the source forest is close the cost per tree should be quite low.   

The tree below was only about five years growing.   


* TreeSpade.jpg (107.29 KB, 531x800 - viewed 953 times.)
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briand
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« Reply #11 on: February 24, 2009, 11:40:24 AM »

Hi - to try and answer your question look at this site
http://handbooks.btcv.org.uk/handbooks/content/section/3767

this quote- suggests that 3 or 4 hectares would cover your needs

A well managed coppice wood containing a full stocking of mixed broadleaved species should be able to produce about 3 tonnes of air dried wood per hectare per year (the old rule of one cord per acre per year is roughly equivalent). Output can be doubled by planting fast-growing species such as willow, poplar or alder. The average figure quoted for heating a three-bedroomed house using wood only is 7-9 tonnes of air dried wood per year, though this figure will vary greatly with location, type of house, insulation and other factors. For most householders, an option of using wood in addition to other fuels is more realistic.

For a three-bedroomed household to be fully self-sufficient in wood fuel would therefore require about three hectares (7.5 acres) of coppice. This could be worked on a ten year rotation, in ten cants, each 0.3 hectare (0.7 acre). Each cant should produce between 7-9 tonnes of air dried wood when cut.
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Justme
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« Reply #12 on: February 24, 2009, 11:42:18 AM »

Do you have your own tree spade? As I have heard that they are very costly to hire in.

Justme
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Bill H
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« Reply #13 on: February 24, 2009, 11:54:45 AM »

For most householders, an option of using wood in addition to other fuels is more realistic.

For a three-bedroomed household to be fully self-sufficient in wood fuel would therefore require about three hectares (7.5 acres) of coppice. This could be worked on a ten year rotation, in ten cants, each 0.3 hectare (0.7 acre). Each cant should produce between 7-9 tonnes of air dried wood when cut.

Greetings.

I agree with this, however it is always interesting to put things in perspective..... 

UK land under some kind of cultivation is around 18 million hectares.
If all that were planted to wood, that should be enough for 6 million houses.

However, there are 25 million households in the UK....   surrender

Wood can help, but it is no silver bullet.

Best regards

Bill



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dhaslam
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« Reply #14 on: February 24, 2009, 12:11:44 PM »

The tree spade belongs to my cousin.   He has one about twice as big as well.    They need a big tractor or JCB to work.   I'm not sure what the charge per days is but it could be something like 1000 euro per day but it becomes quite economical if the source trees are close.   He will have to use a trailer for mine but they should fit on one load.   I am also going to move trees from my old house.   One of the trees is is too big for the spade and he is planning to use a different system, using compressed air to blow the soil from the roots.   
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