Forest of Tronçais
|Forêt de Tronçais|
|Location||Allier, Auvergne, France|
|Area||10,600 ha (41 sq mi)|
|Elevation||205–360 m (673–1,181 ft)|
|Designation||ZNIEFF, Réseau Natura 2000, réserve biologique intégrale|
|Administrator||Office national des forêts|
The Forest of Tronçais (Forêt de Tronçais) is a French national forest, a forêt domaniale, comprising 10,600 hectares (26,000 acres) in the Allier, managed by the National Forests Office. Its oaks, planted by Jean-Baptiste Colbert, minister of Louis XIV to supply the French Navy, constitute one of the principal stands of oaks in Europe.
Within the forest boundaries are the communes of Braize, Cérilly, Isle-et-Bardais, Le Brethon, Meaulne, Saint-Bonnet-Tronçais, Urçay, Valigny and Vitray. It is mainly made up of sessile oak. It also contains 130 ha of ponds and is deemed by many as the most beautiful oakwood in Europe. It is managed by l'Office national des forêts.
The massif is located in the Bourbonnais and Allier department. The oakwood spans the communes of Braize (776 ha), Cérilly, Allier (1788 ha), Couleuvre (405 ha), Isle-et-Bardais (2788 ha), Le Brethon (1400 ha), Meaulne (112 ha), Saint-Bonnet-Tronçais (1176 ha), Urçay (343 ha), Valigny (17 ha) and Vitray (1728 ha).
Located in the INF (inventaire national forestier) "sylvoecoregion" of " Boischaut et Champagne berrichonne ", the forest constitutes the most part of the massif du Tronçais, which spans about 1,200 ha (3,000 acres).
Rainfall is between 800 and 900 mm. Average temperature is 10 °C (50 °F).
The massif has a general north-west orientation, with slight slopes, except in the massif de La Bouteille and stream hollows. Altitudes vary from 205 m (NW) to 360 m (au Bois laid).
There are four big areas : l'Armenanche (east), la Réserve (center), les Landes blanches (NW) and la Bouteille (SW). Several enclaves have created " open areas ". The contours of the écotone/lisières massif are very rugged.
Bodies of water
Beside streams, two rivers fare through the massif : la Marmande and la Sologne. 5 ponds :
- L'étang de Saint-Bonnet (44 ha). This natural pond was enlargened at the end of the 18th century to sustain the level of l'étang de Morat.
- L'étang de Tronçais (18 ha). On la Sologne, created in 1789 to provide energy to aux forges de Tronçais.
- L'étang de Morat (privé) (13 ha). On la Sologne, downstream of l'étang de Tronçais.
- L'étang de Saloup (privé) (12 ha). upstream of l'étang de Tronçais.
- L'étang de Pirot (70 ha). On la Marmande, in operation in 1848 to feed the canal de Berry via l'étang de Goule. 14 m deep.
These are spring sources that have been arranged by humans over time:
There are about 100 springs.
The forest is located on the southern limit of the Paris Basin, on varied substrats (from the primary to the quaternary eras). Most of the forest is located on sandstone or clay from the triassic period.
The principal trees are sessile oak (Quercus petraea) (73%), whose ancient name in French, tronce, gave its name to the district, with beech (Fagus sylvatica) (9%) and pedunculate oak (Q. robur) (8%). There are also hornbeam and Scots pine, which is planted in the poorest soils. Trees are harvested on a rotation averaging 250 years.
The massif plays an important role in the "réservoir de biodiversité" at national level for many species. It also hosts many grove-like landscapes or " paysages bocagers " (bocage bourbonnais, seasonal agropastoral bocage and permanent grassland landscape).
Other nearby massifs:
- la Forêt des Colettes, north of the Chouvigny gorges, spanning over 3000 ha and which hosts a few rare and patrimonial breeds like the Rosalia longicorn, the great crested newt (protected species at European level) or the yellow-bellied toad;
- la forêt de Bagnolet ;
- La forêt de Messarges ;
- La forêt de l'Espinasse ;
- La forêt de Gros-Bois ;
- La forêt de Civrais.
There are predators (such as common buzzard, booted eagle, northern goshawk, hen harrier, etc.) and many breeds of bats. The diversity of insects is also very important, notably in the parcels of the old wood (namely in the futaie Colbert). Important populations of stag, roe and wild boor are regulated by hunting.
Within the forest 108 Roman habitations that have been discovered, most during recent decades, show that the land was cleared and intensively cultivated under the Roman Empire; the resulting pocket of increased biodiversity, initiated by Roman manuring and fertilizing practices, has remained self-sustaining over two millennia and can be detected today.
Tronçais is first recorded from the 13th century, in a document relating to the priory de la Bouteille.
First owned by 14 nearby parishes, then yielded in 1327 to the ducs de Bourbon, la forêt de Tronçais belongs to central power since 1527, when it was confiscated from the Connétable de Bourbon by royal power, along with all his land possessions.
The forest is not a relic of the primeval forest that once covered most of France, but was organized by Colbert in 1670, with forethought for the requirements of the French Navy two hundred years hence, the present futaie Colbert, now reduced to a few hectares. Beeches and larches were interplanted with the oaks to encourage them to grow with straight tall masts free of knots.
By the time the trees were fully mature, the navy was rapidly switching from sail to steam. The forest was diminished by the creation in 1788 of iron forges fed by charcoal from the forest, and by urgent cutting during the French Revolution and the Napoleonic period. The forest regenerated during the 19th century.
The oaks of Tronçais, representing some 80% of production, are prized for the barrels coopered for cognac and the great wines of Bordeaux. Amongst the more famous coopers using the oaks of Tronçais are Dominique Laurent who makes what are widely regarded as some of the world's finest barrels. These have been nicknamed "magic casks", by renowned French wine taster Michel Bettane. Laurent goes into the Tronçais forest to select the trees (typically around 300 years of age) and transports them back to the cooperage himself, thus guaranteeing provenance. He only uses the top section of the trunk, the staves are split by hand and air dried for 52 months. The staves are much thicker, due to their hand splitting, compared with commercial barrels, (40-45mm as opposed to 25-30mm approx). The barrels were developed for Dominique Laurent, and Tardieu Laurent's top cuvees but a few of the barrels are sold to (only) the best French and international producers including DRC, Zind Humbrecht, Clos Mogador, Pingus and Beau Fréres from Robert Parker Jr. in Oregon. A limited number of barrels make it to Australia where they are used by the boutique winemaker Torbreck for the making of Australia's most expensive (and 100 point rated) Shiraz - "the Laird".
The wood has:
- few nodes
- growth is fine and regular
- Raw quality : the wood has an appreciated pink colour and chemical composition
La futaie Colbert
The oldest forest trees are in la " futaie Colbert ". It is a 13 ha parcel, of which most trees are from the end of the 17th century. These are ranked as réserve biologique dirigée, sylviculture is no longer practiced, in order to favor of biodiversity around deadwood and senescent trees.
La futaie Colbert spanned 73 ha in 1976, of which 60 were regenerated from 1976 to 2001.
Sculpted trunks have been stalled in the forest's clearings by l'ONF and la communauté de communes du Pays de Tronçais in 2008, 2010 and 2012.
- Coordonnées en décimales, relevées à Tronçais à l'aide de Google Maps
- A forêt domaniale is a category corresponding to the French State's inalienable domaine, as heir to the monarchy, under a judicial regime distinct from the national patrimoine and from private property, defined by a royal edict issued from Moulins in 1566. (French Wikipedia: Forêt domaniale).
- DREAL Auvergne (2013) Prédiagnostic des continuités écologiques en Bourbonnais et Basse Combraille
- ONF (juillet 2011) La sylviculture du chêne à Tronçais La sylviculture du chêne à Tronçais (document distribué à l'occasion d'une visite lors de l'assemblée générale de la Société des amis de la forêt de Tronçais
- moyennes 1961–1992 sur 3 stations
- "How Roman farmers left their mark on nature". www.world-science.net.
- Une forêt domaniale : Tronçais, A. Pees, Office national des forêts, n°4, octobre 1967, p.9.
- Allier Tourisme: The Tronçais Forest
- The forges established by Nicolas Rambourg remained in use until 1932.
- (in French) Forest of Tronçais on the website of the Office national des forêts