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  • From: <scott@permaculture.org>
  • To: permaculture <permaculture@lists.ibiblio.org>
  • Subject: Re: [permaculture] Earthships
  • Date: Sun, 31 Jul 2016 08:12:40 -0600

Thanks Ossi for re injecting a little gravitas into this conversation -
Welcome!!


> -------Original Message-------
> From: ossi@kulma.net
> To: permaculture <permaculture@lists.ibiblio.org>
> Subject: Re: [permaculture] Earthships
> Sent: Jul 31 '16 05:16
>
> 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
> >>>>>
> >
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