[Strawbale] Sustainability of wood heat.

[Corwyn]

On Jan 31, 2008, at 01:02, Sherwood Botsford wrote:

> Speireag Alden wrote:
>>
>>
>>      No.  Burning wood produces particulates and ashes, and most of
>> the time the wood is not harvested sustainably, though in theory it
>> can be.  I would not use wood in an application where you will lose
>> 70-80% of your input.
>
> Particulates depend on how well you run the stove.  Poison and 
> pollution
> are matters of concentration.  I have 12 neighbors within a 4 mile
> radius.  That's 1 neighbor per 900 acres roughly.

True, but until you provide the mechanism for them to convert to 
something else, you get to sum over the entire planet.  Thus, you have 
7 billion 'neighbors'.  Note, I am not saying there isn't one, just 
that if you don't know what it is, you have to assume their isn't one, 
and that poisons and pollution are accumulating and becoming more 
concentrated.

> Ashes are fertilizer. (Potassium and phosphorus) One of my spring 
> chores
> is to take the ashes out to the wood lot ans spread them around.

Good for you!  Mine mostly end up on the gardens.

>  Harvesting sustainable is not rocket science.

Right.  If only it were as simple as rocket science.

> Here's how I figured it:  By looking at stumps the mature black poplar
> on my land are between 80 and 120 years old when they start to die off.
> Often the time after age about 60 is pretty slow growth.  Ok.  We'll
> assume 100 years for a mature tree.   On that basis I can harvest about
> 1% of the tree biomass per year.  This ignores the much faster growth
> while young, the biomass in the understory.  With much thought and
> study, I could remove 3-4% of the biomass per year.

I am not sure what you are saying here.  How do you get from how long 
one (short-lived) trees last, to how much you can sustainably harvest?
>
> So that means I can harvest about 1% of each class of tree.  In 
> practice
> I ignore the stuff under 4"  And I ignore the patriarchs (too hard to
> split) unless they look like they are going to hit the house.  the best
> size for my time are about 16" at the butt, and 60 feet high.
>
> A cord is about 300 chunks, where ia chunk is 16" long by about 7" in
> diameter.  60 feet of tree makes 45 lenghts, averaging 3 chunks per
> length.  135 chunks per trunk.
> I can get a few more from the bigger branches.  So two trees per cord.

If you are getting a cord out of two trees, I am impressed.  I 
seriously doubt those are 100 year old trees though, unless they grow 
them bigger there.   It takes me at least 10 trees to make a cord.

> 20 trees per year of heat. That's probably an over estimate.  This year
> looks like it's going to be a 6 cord year.  And I think it only takes
> 1.5 trees to make a cord.  Carry on!

Tens cords is a lot.  I burn 2 for a 7500 Degree day climate.

> My woodlot is about 12 acres.  So I have to cut not quite two trees per
> acre on the average to get 10 cords. Or ten 8" poplar per acre.   At 10
> foot spacing there are over 400 trees per acre.  (And yes 10 is more
> than 1% of 400, but it was 1% of all age classes.  I usually end up 
> with
> a mix of sizes.)

You are getting 1.5 cord trees every 10 feet!?  All I can say is wow.

> As a mark of our success:  Our pair of piliated wood peckers have
> successfully raised a brood each year. (5 of them on the platform 
> feeder
> at once!)  Both kinds of nuthatches fledged their flocks, and the downy
> and hairy also succeeded.

I am not sure how conclusive that is.  I suspect that the piliated at 
least is using more than your 12 acres.  Mine is doing well as well, 
and he just had 50 acres clear cut in his territory.

> My conclusion:  Do I have an impact? In the long term, yes.  Is it
> sustainable?  In the long term, yes.

Maybe.  I am not sure anyone knows what it would require to be 
sustainable.  We do what we can, then we do more, and we hope.

>  Do I have much of an alternative in this climate?  Not really.

Sure.  Get that 10 cord number down to 3. or better.


I want to emphasize that I think you are doing well, just that I don't 
think anyone can think we are done yet.

Thank You Kindly,

Corwyn

-- 
Corwyn
Kermit didn't know the half of it...
http://www.greenfret.com/
corwyn at greenfret.com