Forestry and wood energy

Renewable energies except solar electric or thermal (seeforums dedicated below): wind turbines, energy from the sea, hydraulic and hydroelectricity, biomass, biogas, deep geothermal energy ...
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Did67
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Re: Forests and wood energy




by Did67 » 19/07/19, 16:23

Yes, I probably did not speak well - in any case we misunderstood: there was an error in the legend of a photo of the first edition. In the photo, it is a forest regular. And I had put "forest gardened"(which is irregular) ...
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Re: Forests and wood energy




by Ahmed » 19/07/19, 20:07

No, it was clear, reassure yourself, and I understood, I just wanted to insist on the inherently irregular nature of the high forest, which is useless for those who know a little, but not for the Boeotians ...
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Re: Forests and wood energy




by sicetaitsimple » 19/07/19, 20:19

Ahmed wrote:No, it was clear, reassure yourself, and I understood, I just wanted to insist on the inherently irregular nature of the high forest, which is useless for those who know a little, but not for the Boeotians ...


Well, I did not understand anything, but in terms of forestry I am less than a Boeotian!
A small explanation of text?
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Re: Forests and wood energy




by Ahmed » 19/07/19, 21:05

No problem! 8)
A regular high forest is a plot on which are trees mostly of the same species and age; to manage the rotations, the forest is composed of a certain number of plots corresponding to different vegetative advancements and, with the ad hoc shift, the silvicultural interventions, until the harvest, will take place successively on each plot ...
The irregular high forest works "out of order": age classes and species are mixed and interventions are carried out on the entire stand according to each particular situation, hence the qualifier of "gardened" since they are not concerned only small areas at a time ...
The rejuvenation is done preferentially by natural regeneration, using the spontaneous seedlings to which a place is made thanks to a progressive lighting ...

Questions? I hope I'm clear? The science that comes closest to silviculture is sociology ... And if I believe Lessewattit does not help! :D
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Re: Forests and wood energy




by sicetaitsimple » 19/07/19, 21:24

Ahmed wrote:Questions? I hope I'm clear?


It's perfectly clear, thank you! :D
Like what when you explain me with simple words, I can understand! :D

Maybe this is also the problem of Moindewatt?
Good week-end.
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Re: Forests and wood energy




by Ahmed » 20/07/19, 11:57

I come back to the subject of this thread. I reread the beginning and I do not agree with the words of woodcutter which asserts that only young stands are able to accumulate a lot of CO² and that, therefore, it would be rather innocuous, even desirable, to cut down the old ones and replace them with new ones.
This is not what emerges from what I read on the subject and I think that his opinion results from an observation bias: it is more obvious to see visually the changes in a young forest than in a stand adult. Adult trees grow in diameter and this gain is spread over all individuals, it is far from obvious without serious measures ...
One thing is certain: carbon accumulation is mainly a function of the solar collector area per unit area.
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Re: Forests and wood energy




by Did67 » 20/07/19, 14:07

I think that the amount of CO² permanently stored by a forest should look like a "bell curve":

- young, the "reforestation" is partly herbaceous; the stored CO² is released fairly quickly (mineralization); it is not yet a forest ...

- then, it becomes a forest, which permanently stores C in lignin, layer after layer; only a small amount is "recycled" each year: the leaves ... A part of this fresh non-woody material is humified, so is also sequestered ...

Here, we can estimate that the quantity stored will depend on the growth of the standing stock. I confess I do not know the curve. Quite quickly, it seems to me that the limiting factor is the incident energy, and so it should be stable. It does not matter that some trees grow a lot and many small trees grow little ... It seems to me.

- then, an unexploited forest tends towards a balance; the oldest trees die and are partly militarized; apart from the formation of humic substances, which also stabilizes (balance between mineralized substances and those formed, around a rate of 5 to 6% in our climates) and apart from the training of soluble humic substances such as those entrained by the Amazon towards the sea (which does not seem to me to happen in our climates), it seems to me that we have then reached an equilibrium; and therefore that the forest is no longer a "lung" at all, but a stable system that consumes as much CO² as it emits ...

- Of course, in an exploited forest, it is the destination of the wood which will determine the balance sheet: if it enters Notre-Dame of Paris, it is durably sequestered, while waiting for the next fire ... If it is is firewood or pellets, it is immediately put back in circuit. And if it stays in place (branches, roots), we are in the cycle of mineralization and humus ...
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Re: Forests and wood energy




by sicetaitsimple » 20/07/19, 14:38

Did67 wrote:- Of course, in an exploited forest, it is the destination of the wood that will determine the balance sheet.


It seems to me the most important, at least on a "human" time scale. What Amhed is telling us is certainly correct, but the limit is growing a healthy tree, capable of producing good quality timber.

PS: "the oldest trees die and are partly militarized". No, we are no longer at the time of the Navy Colbert! : Lol:
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Re: Forests and wood energy




by Did67 » 20/07/19, 15:21

sicetaitsimple wrote:
PS: "the oldest trees die and are partly militarized". No, we are no longer at the time of the Navy Colbert! : Lol:


Oops, slip written. I can no longer edit. Everyone understood, I think, that it was necessary to understand "mineralized" ...
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Re: Forests and wood energy




by Ahmed » 20/07/19, 16:07

We look forward to seeing you! Did, to have specified in a more global way the evolution in work: indeed, carbon storage does not grow to infinity! :D Without human intervention and under stable stresses, a dynamic equilibrium finally appears between storage and release of carbon.
What is important to understand is that each "reset of the counter" (clear cut followed by planting) induces a lasting deficit in carbon capture, despite appearances more satisfactory for unsuspecting minds. . This is what motivates the propaganda that justifies the abusive levies for industrial wood boiler rooms which are presented as exempting us from the disadvantages of conventional boiler rooms and therefore exempting us from questioning our operating model.
Another idea which distorts the judgment of those who are only concerned * with numbers and who are blind to the realities which, unfortunately, they hide much more than they describe them, is the French forest expansion. Indeed, if it is very real mainly due to agricultural abandonment, the areas which are thus counted correspond mainly to administrative categories and take into account a large number of poor or degraded populations that a field examination would not readily do. enter under the denomination "forest". However, destroyers of all stripes are excited about these statistics, finding there a pretext for their dangerous delusions.

* But also the judgment of many others, consequently ...
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