permaculture

[ossi@kulma.net]

Hi Toby et al.

Sorry to tell you, but it seems like you have not explored this issue 
enough and I suggest you are wrong with the proposed assumption 
regarding carbon storage in trees.   Such growth pattern you describe as 
universal would apply only on trees grown in cleared open areas, f.e. 
after a clearcut or as if timber is left in seed-tree positions after 
harvest.   Now if we compare to old growth forests this "universality" 
does not apply.  As an example I have found more than 100 year old 
spruces grown from total darkness of dense undergrowth so that they are 
only apx. 15 cm in diameter but when dead seem to be more durable in use 
than most of the metals I know about.  That kind of wood is heavy even 
if is totally dry.  In any of the (semi)natural boreal forests I've seen 
that "universal" pattern you describe doesn't apply unless it disturbed 
strongly by human intervention, which equals to collapse in amount of 
stored carbon.

Rate of growth is very simple thing but big growth rings do not relate 
to with how much carbon is stored in the tree.  You can have 3 times 
fatter tree grown in 15 years, but when you  cut that tree down and dry 
it - it can be lifted with single hand as there is not really carbon 
stored in their cells, but rather empty space between relatively fragile 
cell walls and their fresh weight was due to enormous amount of water 
that was there.  Due to large cell structures that kind of fast grown 
wood doesn't really have any other use than to shade ground for natural 
forest to regenerate with accumulated density, which stores the carbon 
for longest periods available.

In contemporary Finland current construction wood sales are providing 
mostly too low quality wood, so that they need to make composite 
elements out of the wood-material available and therefore it is becoming 
rare to find single timber being publicly sold as construction wood - as 
they do not have much of such timber available due to unsustainable 
forest  management which was widely adopted since the 2nd world war.   
I'd think that old trees that grow slowly have just achieved their 
adulthood and would likely store at least 1000 times more carbon both in 
dry weight and durability in time than any fast grown crap from the pulp 
plantations.

So what comes to the forest management practice you describe, yes that 
is useful in terms of fast supply for timber (which can be stored in 
buildings for 500 years as you say), but do not relate that to optimal 
carbon storage of trees as their capacity under such management is not 
even nearly the optimum that can be achieved.  Also in terms of ecology 
leaving the oldest trees growing should also apply especially if 
permaculture principles are seriously taken under consideration.  I 
strongly suggest that maths regarding such issues should follow logic 
like this: more density, more carbon there will be stored and more 
durable that carbon is within extended periods of time.  Of course there 
is somewhere a point where the growth rate could be too little and cells 
get fragile due to that, but generally in GOOD quality trees one likely 
cannot read the growth rings without magnification as they are far less 
than 0,5 mm.

Second thing that I would like to mention is that when trees "rot" in 
forest they do not release all their carbon as CO2 into atmosphere as 
under such conditions any CO2 released would be heavier than air and 
therefore unless being technologically shot up into the sky would float 
under forest canopy and would be most of the year captured directly at 
least by conifers or their lichen partners.   Also a lot of carbon that 
was in decomposed wood especially in case of the old growth forest would 
be circulated by fungi within the system and be either stored in soil or 
in community of living beings.

Now, please keep up the good work you're doing.
Thank you for you are and kind wishes for all sentient beings.

Ossi Kakko
(Eastern Fennoscandia)




Toby Hemenway wrote  2016-07-28 06:51:
> Scott’s comments are excellent. I would add that the rate at which a
> tree sequesters carbon is also dependent on where the other trees are
> . Nearly all species of trees slow their growth rate enormously once
> the canopy closes as they compete with other trees for light and
> nutrients. I’ve looked at tree rings on many species of both hardwoods
> and softwoods, and the pattern is universal: fast growth (fat growth
> rings) for the first 20-60 years, then only slow growth after that.
> They store most of their carbon in youth.
>
> Solution would be to selectively log when the canopy closes to open up
> light gaps so the other trees can keep growing fast. Then cut those
> when they slow down, and plant new trees in the gaps. Put it all in
> structures that last 500 years.

> > On Jul 27, 2016, at 5:53 PM, scott@permaculture.org wrote:
> >
> > In the case of fast maturing trees that are harvested at maturity 
> > would be excellent building materials.  But trees that are still 
> > growing should be allowed to continue to sequester carbon.
> >
> > > -------Original Message-------
> > > From: Scott Vlaun <scott@moosepondarts.com>
> > > To: permaculture <permaculture@lists.ibiblio.org>
> > > Subject: Re: [permaculture] Earthships
> > > Sent: Jul 27 '16 15:39
> > >
> > > To Georg's point, sequestering carbon in well built structures made 
> > > from wood harvested sustainably. Here in Maine there are short lived, 
> > > fast growing species like balsam and poplar that make decent building 
> > > materials and would otherwise die and quickly release carbon as they 
> > > rot in the forest.
> > >
> > > Scott Vlaun
> > > Center for an Ecology-Based Economy 207 520 0575
> > >
> > > > On Jul 27, 2016, at 5:33 PM, Scott Vlaun <scott@moosepondarts.com> 
> > > > wrote
> > > >
> > > > My mother in law lives in a 25 year old earthship in NM. I've spent 
> > > > a lot of time in it and it is pretty fantastic. Can and bottle walls 
> > > > eliminate a lot of carbon intensive concrete as do massive Adobe 
> > > > thermal mass walls. The sculptural aspects, especially tile mosaic 
> > > > make for a very Inspired living space. Embodied energy per sq. ft. 
> > > > on these structures is extremely low and even in northern NM she 
> > > > gets by on less than. Cord of wood per year, only needed when cold 
> > > > and cloudy. I'm extremely sensitive to tire outgassing and have 
> > > > never even gotten a whit. Labor intensive to be sure though!
> > > >
> > > > To
> > > >
> > > > Scott Vlaun
> > > > Center for an Ecology-Based Economy 207 520 0575
> > > >
> > > > > On Jul 27, 2016, at 5:07 PM, Georg Parlow <g.parlow@gmx.at> wrote:
> > > > >
> > > > > Thanks Lawrence and Scott for this dialogue. Valuable.
> > > > >
> > > > > However, one question, Scott:
> > > > >
> > > > >
> > > > > > **Whenever possible eliminate using forest products in 
> > > > > > construction.  The wood is much better used as a carbon sink.
> > > > >
> > > > > To my understanding wood IS a carbon sink - and if it sits in my 
> > > > > house for 200+ years this is just as fine as sitting (and maybe 
> > > > > falling over and rotting) in the forest. What is it I do not see?
> > > > >
> > > > > Georg