The Great Green Wall against the advance of the Sahara

[Christophe]

A big project of reforestation to fight against the advance of the Sahara ... I knew the local initiatives but I did not know a project of so great magnitude and it is 8 years that it began ...

How to stop desertification, accentuated by global warming? In Africa, the solution passes through the Great Green Wall, a vegetal strip that is planted on the edge of the Sahara, throughout the continent.

http://www.pourlascience.fr/ewb_pages/a ... -35982.php

[Did67]

There was a precedent in Algeria, under Boumedienne, in the 70s. The army had been mobilized on a very large scale. "Socialist" governments have always had a penchant for major works, diverting rivers, stopping the desert, building a cottage (Ceauscescu), dam of the 3 gorges of Mao, program of 1 dams of Sankara in Burkina (000 , I'm not sure; well, these are small village water reservoirs, it was infinitely crazy months!) ...

Mixed success. I'm talking about the green barrier.

But we can still find significant traces of this barrier, where she took. In many places, alas, it had burst. The population had also partly looted, recovered fences, delivering seedlings to the teeth of goats, etc ...

See for example: https://www.unece.org/fileadmin/DAM/env ... geVert.pdf

A balance a little more critical: http://alger-roi.fr/Alger/agriculture_a ... e_vert.htm

[77% of planned areas achieved; Survival rate at 3 years: 42%]

So nothing new.

Farther back in time, do not forget that the forests of the south and south-west of the Massif Central, around Mont Aigoual, Mont Lozère were created from scratch to fight against the erosion and siltation of the port of Bordeaux and flood, from the 1860 years, following laws on reforestation (part of which is still in force, including the almost absolute prohibition, except in cases of public interest, to shave a forest!).
Today, all these massifs seem so natural! These peaks were then laid bare by clearing, clearing, the production of wood and charcoal, etc. The consequence of this deforestation: massive erosion. See "Georges Fabre", the polytechnician who was the great instigator of all this, who has his monument at Mont Aigoual ...

[Did67]

Uh, I forgot. But this story of great barrier against the advance of the desert makes me gently go for it.

1) The "mass" that represents the Sahara, will surely not be stopped by a strip of trees 10 or 15 km wide. It is not, on the scale of the Sahara, even a "string".

But in the photo, on the desk of a minister or an expert or even an NGO collecting funds, it can look pretty!

No doubt there is also money for "carbon compensation", good conscience of all those who pollute with fossil fuels (they contribute to plant x thousand trees, and voila).

2) More broadly, desertification is not just the actual disappearance of trees. It is a complex process where warming combines with overpopulation (and its needs for wood, land, pastures ...) and management methods that are currently inadequate (the straying of animals, the heritage or social value of animals: is rich who has many animals, the endowments are paid in animals so a young male must capitalize ...). Etc ...

To install a band of trees when such phenomena are involved is to pee in a violin. Although surely, here and there, it will have a beneficial effect. If only wood for women ... or craftsmen.

[chatelot16]

where the climate makes the trees disappear it is useless to plant them to let them die ... if the natural conditions are not good it is necessary to help the nature with technical means ... means of conserving the water for example ... but I will not put a layer on my idea to cultivate the desert that I have no chance to put into practice

on the other hand the same problem arrives in France ... I see around my home of the forest to be cut to the raz, only to make firewood ... even large trees which seem to me to have value are cut in small piece

I want to buy ten hectares to replant my way: it turns out that around my home there is not enough water for the tree grows well in summer: beautiful trees crevent thirst, it diminishes the chance to have beautiful tree for quality wood ... to have beautiful wood should plant tight enough for it to grow right without big branch low knot ... but if there is not enough water to grow trees tight it does not go ... my solution is to mix the forest and the agricultural or industrial building ... the building does not consume water and leave it to the trees, and if it has just the right height it pushes the tree to climb without a low branch

of course the forest plot is currently unbuildable ... but the current regulations should not be questioned with a little common sense? should not we plant more trees in industrial areas and build buildings in the forest?

in France the shortage of building is as serious in housing as in industrial building ... in the forest around home I am convinced that if part of the surface was intelligently built the wood part would make the best wood

my remarks are a little off topic here, I intended to create a subject "industrial drill" but this subject is still an opportunity to talk about it

[Ahmed]

There is a set of empirical and / or rational agronomic practices that deserve to be disseminated to the populations. It is not sure that this is enough to stop the desert if the climatology remains unfavorable, but this can prove useful in many border zones. In any case, much more judicious than these plans too ambitious, imposed from above and likely to be rejected or misunderstood by the local populations (whose needs concern only incidentally decision makers) ...
Many areas with prosperous agriculture in hot climates rely on pumping in fossil aquifers and are therefore eventually condemned: for these, no plan B without breaking with the extractivist dogma.

The sprawl of forests by buildings is potentially an explosive mixture: the difference in temporality in production is such that this imbalance would be to the detriment of the forest. In addition, the issue of natural pruning obtained by this means is more than questionable!

[chatelot16]

ahmed your answer shocks me ... when we plant tightly so that the tree grows straight, if there is not enough water it grows badly, in the middle of summer when there is a lot of sun that should make photosynthesis work it does not work for lack of water

by reducing the wooded area and mixing with other construction designed so that the wooded area produce at full capacity all summer without running out of water

by answering I prolong the off topic ... my problem is to value the forest product ... there is only the log that is valued ... to value the brf, the wafer, the compost ... need space and storage building ... and currently around my home we do not value anything properly for lack of storage medium

it confirms to me that mixing building and forest is a way of the future

[Ahmed]

For my part, it is your reasoning that strikes me: how could the neighborhood of buildings substitute for a vegetal accompaniment?
In the middle of summer, plant physiology "predicts" a slowing down of the growth of the stems (maximum during spring), it seems difficult to overcome this constraint.

If we take into account the development of biomass power plants, there is hardly any more to worry about the quality aspect of the forest, since the volumes concerned will be such that everything will have to go through the "mill"!

* Which aims more at the natural pruning than the straightness of the trunk (it contributes indirectly to it, since the selection of the stems to preserve is easier with a high initial density).

[chatelot16]

everything to go to the mill for heating seems to me sad ... to make good wood for various construction is much higher, go to the mill for heating should be only for falls

I see that we do good wood in countries where it rains a lot, where the trees do effective photosynthesis all summer

if in months there is not enough water to do effective photosynthesis for everyone, you have to organize differently

it's a general question: there are urban or industrial areas where rain is useless ... there are forests where there is not enough water ... it would be necessary to make a mixture between the 2

[Macro]

I work in an industrial area or now more than 50% of buildings are no longer needed for nothing .... In the middle of which was established a biomass heating plant ... Gigantic ... I did a day buggy ride on Angouleme two weeks ago ... I did not find that it lacked water..Ni forest ...

[chatelot16]

For my part, it is your reasoning that strikes me: how could the neighborhood of buildings substitute for a vegetal accompaniment?
In the middle of summer, plant physiology "predicts" a slowing down of the growth of the stems (maximum during spring), it seems difficult to overcome this constraint.

If we take into account the development of biomass power plants, there is hardly any more to worry about the quality aspect of the forest, since the volumes concerned will be such that everything will have to go through the "mill"!

* Which aims more at the natural pruning than the straightness of the trunk (it contributes indirectly to it, since the selection of the stems to preserve is easier with a high initial density).

in the forest of which I speak there is not enough water for all that pushes thus stop in summer: if a part of the surface is occupied by building with recuperation and storage of water it will make more water available for what we want to grow

I see clear cuts being made around my home, even beautiful trees are cut in firewood because the timber trade is poorly organized

poor wood valuation also comes from lack of available building and lack of sawmill