Aigronne Valley Wildlife pages

Showing posts with label restoration. Show all posts
Showing posts with label restoration. Show all posts

Thursday, 4 December 2014

Weir, art thou going? River improvements part III

Our posts here and here about the programme of improvements to the Claise basin described the achievements in our corner of the Aigronne valley, out of 77km of river bank works in the last three years.

Now operations have started on the section of the Claise between Le Grand Pressigny and Etableau. If you go down the rue des Réaux towards Abilly you will see, or rather you won't see, the familiar line of poplars screening the decaying former furniture factory building near the déchetterie.

Stumps, logs and branches next to the Iron Bridge
The trees that remain, apart from the big oak, are mostly small alders.

View towards the weir from the Iron Bridge. The house behind the high hedge to the right is for sale.
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See "Improving the Aigronne Part II" for a translation of the poster
Poplar is an excellent timber, widely used for construction throughout France, and good poplar wood is valuable. The tradition was, when a daughter was born, to plant a poplar plantation to pay for her dowry when she got married. But these trees were too far gone. The smaller notice describes how the trees will be disposed of. Given that a Prefectorial edict obliges the commune to do the work; that turning dead and fallen trees and branches into biomass is not easy to do cost-effectively; and that the cost of hiring the mulching equipment needed to compost the remains is beyond the resources of the town council, SARL ETREN is authorised to burn what it cannot turn into biomass.

The field behind the digger is scheduled as building plots
The poplars were rotting at the heart, potentially dangerous, and they had to go. The weir is in the background.

You can read the small poster if you can fly. But it's important!
Be that as it may, the poplars were in the way of the really big undertaking.   Under the European directive on water courses and La loi sur l’eau et les milieux aquatiques (LEMA), the commune has to remove (literally, to "suppress") the weir, and return the river to a semblance of its original state. Given that water mills have been in existence since classical times, we are talking prehistory here.

La Nouvelle République in its article of 22nd November 2014 describes the weir project thus:
in May 2015, the barrage will be removed and the bed of the Claise re-aligned, rebuilding part of the banks with rock, earth and pebbles, with the objective of reducing the width, giving back to the river an appearance of the original bed, permitting the water level to rise and restoring the rate of flow.
The weir from the town bridge
The weir was built in the 1970s to provide a swimming area and sustain the water level in periods of low water. It is now obsolete. Nobody wants to swim there: the water is dark and forbidding, the bottom is squidgy and covered with leathery, slippery poplar leaves, and there's a heated public swimming pool on the other side of town. La NR continues:
the prefectorial mandate governing the operation of the weir obliges the commune to keep it open for nine months of the year. This obligation has never been respected. The repeal of this mandate will require the community of communes of Touraine du Sud (CCTS) to remove the weir and return the site to a fit state. The CCTS's land management brief makes the work possible. A partnership with the region [Centre], the département [Indre et Loire] and the water agency [for the Loire and Brittany] allows the rehabilitation of the site to be incorporated in the restoration program. This new project will be 100% subsidised.
 See also the CCTS web site here and here.

Suppress the barrage? Sounds simple enough. No big deal. A bigger deal will be the heavy lorries thundering past carrying the "rock, earth and pebbles" to the site and thundering even louder as they return empty at top speed. A major issue will be disposing of the tonnes of concrete of the barrage itself and the spillway, and the unknown tonnage of silt (la vase) deposited behind the weir. Where will it go? How much is there? How many lorryloads?

And just what is meant by the river's original bed? When the ground is saturated, it is easy to trace old meanders of the Aigronne, for example in the fields south of Rivau. The Claise valley between le GP and Descartes opens out to become several kilometres wide, the site of a prehistoric swamp/lake bed. Watermills go back to the times of Alexander the Great; human life in the Aigronne and Claise valleys goes back to the Upper Palaeolithic, 350,000 years ago. How far back should we go in restoring the river to its "original state"?

For us, the biggest issue of all will be when the sights are turned on Richard's weir and sluice gate that direct  the Aigronne's flow into the bief that runs past our house and the Moulin de Favier. That weir has been there for at least two hundred years, and is shown on the Napoleonic cadastral map of 1812. The mills existed when the Cassini  maps were drawn in the 17th century, and, since La Forge was an undershot mill, there must have been a weir too. The Cassini map does not show such fine detail. The sluice is new (1980s) and was constructed along with the étang. It is left permanently open.

The Dechartes have a history of the Moulin de Favier going back to the 12th Century. The habitat supports at least one nationally proteced species - the water vole - and local rarities like the Large Pincertail dragonfly. We have a duty to preserve la patrimoine, be it history or nature. On the other hand, everyone has a right to clean water, including the migratory fish such as eels which are blocked by such barrages.. I'm not quite sure how turning our bief into a stagnant ditch full of mosquitos will improve the milieu aquatique.

And the history of Le Moulin de la Forge is a matter for another post.

Thursday, 21 November 2013

L'éperon Murat : attention, fragile!

So read the headline on page eleven of Sunday's La Nouvelle République....
and it was an article about the new plans for the site that we wrote about here as part of the post on Sunday 20th October.

So whilst I took advantage of the "drier" weather to scalp the areas of grass we tread most...
Pauline translated and summarised the article.....

La Nouvelle République, 17 novembre 2013
L'éperon Murat, warning, fragile!

It is one of two sensitive natural areas in the Loches area.
L'éperon Murat (the Murat Spur), at Ferrière-Larçon, benefits from protection which is entering a new phase.
About a hundred sheep are pastured on the Murat Spur, where the Larçon joins the Brignon. This is one of the headline actions undertaken for a decade aimed at preserving this sensitive natural environment (1).
The objective is simple: the animals participate in the maintenance of the dry grassland of this promontory, an environment which has become rare in the region (2).

Protection of the Murat Spur, act II
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The Conservatoire d'espaces naturels (CEN) of the Centre region is studying a management plan which is nearing completion. At Ferrière-Larçon a couple of weeks ago, the assocation made public the new plan for the next ten years. In broad outline, the planned actions are much the same as those to date.

The extensive sheep pasture, which was re-established in 2005, will continue, in collaboration with the same farmer, Pascale Jacquet from La Celle-Guénand.
The sheep-farmer has the use of the land rent-free,
In return he must follow a list of exact duties.
"I am not from a farming background", explains M. Jacquet, who practises "agriculture raisonnée" [minimum intervention agriculture #] and sells direct from the farm.
"When I wanted to go into sheep, I didn't have room. So I accepted the proposal. I apply something very like the system of transhumance in the mountains."
Of his 250 ewes, between 30 and 100 are thus pastured on the Murat Spur.

"It's typical of what we're trying to do in environments formerly maintained by farmers and which, difficult to get to, are no longer of interest for traditional farming", explains Rolland Paillat, scientific study officer at CEN and principal author of the 2014-2023 management plan.
[It is also similar to the principle of the "Flying Flocks" and other conservation grazing as used by The Wildlife Trusts  and others in the UK.]
A more overgrown area
The restoration of the grassland will therefore continue.
This will happen notably by the removal of numerous pine trees which will give air and space for other plant species. In particular, the eight protected plant species (all orchids) and the twelve other regionally uncommon species, such as the Summer Pheasant's Eye [Adonis aestivalis] Adonis goutte-de-sang which the Murat Spur is home to.
That is without mentioning the varied fauna which lives in the 31.5 hectares of the site, owned by the conseil général.

The Junipers, that can be seen behind the oak and the orchids [ Cephalanthera sp.]
in this picture, are encroaching quite rapidly in some places... the sheep don't eat it!


In all, over the next ten years, 250,000 € is expected to be invested to safeguard the Murat Spur.
(1) With Les Prairies du Roi on the outskirts of Loches, it is one of two Sensitive Natural Spaces in the Loches area.
(2) Mainly financed by the Region and the conseil général.
Facts
Where...
The Murat Spur is one kilometre south of Ferrière-Larçon, along the D50.

Area...
31.5 ha acquired by the conseil général

Types of environment...
Chalky dry grassland, oak woodland (pubescent and sessile), heathland...

A close up of the turf.
Flora...
More than 360 plant species, including eight regionally protected species (Man Orchid, three Cephalantheras: rubra, longifolia and grandiflora, Small Spider Orchid Pyrenean fragrant orchid, Violet Limodore, Burnt Orchid and Pyramidal Orchid).

Fauna...

Nationally protected: Large Blue butterfly, Western Whip snake, Western Green lizard. Also nine species of bat, which will be the object of particular attention in the new management plan. This is notably to preserve their hibernation hollows.
The maintenance of the ripisylve* of the Larçon will also be an objective of the management plan.

[Links in the above three sections go to Loire Valley Nature.]

Visit...

The site is open to the public (sic).
Two organised visits take place annually by CEN on the theme of orchids.
Contact www.cen-centre.org.

(*Riparian forest = natural woodlands beside watercourses)
(# Similar ideals to the Wholesome Food Association's rules)
Five more hectares...
A particular effort will focus on the hillside of Montaugon, a plot of a little less than five hectares recently acquired by the conseil général.
"It is an environment similar to the Murat Spur, about 500m away as the crow flies, which has long been abandoned.  The first tree-felling work has started", Rolland Paillat from CEN commented.

The full article is here...

Now some more pictures from L'éperon Murat...

Hybrid Lady Orchid [possibly Lady x Man]

Milkwort thriving in the short turf left by the sheep.

Variations on Spider Orchids
Burnt Orchid
A couple of 'hoppers
A pale Green-winged Orchid
Cephalanthera longifolia
Fly Orchid
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CRANE UPDATE: Cranes on weather radar!

Follow this link to see the migration of the cranes on the 13th of November...
showing up on the Rain Radar on Meteo60 [http://www.meteo60.fr/]...
32,700 Cranes left Lac du Der in the space of around 4 hours... starting at 8AM.
There are three weather radar clips on the entry for the 13th...
each showing various quantities of birds.
It would seem that some reached Gallocanta in Spain the following day...
their count went from 14,000 in the morning of the 14th to 39,000 by the evening!!

Not counting the 28 500 that remain at Lac du Der...
there are still over 50,000 in North Germany that are still on passage!!