Zoom on Tronçais forest, an exceptional heritage27 February 2018
The Tronçais National Forest has an exceptional influence amongst French forests, an influence that goes well beyond mere national borders.
It is generally thought that Colbert was behind renewal of forest management in Tronçais. It is true that under his direction the forest was enclosed to protect it from abuse from local people, just like all the other royal forests of the time. But after this period of reformation, the forest was subjected over 50 years to the «tire et aire» parcel felling that was traditional under the ancien régime. This was clearcutting, parcel after parcel, retaining a reserve of seed trees in accordance with the order of 1661, i.e. 10 trees reserved per arpent. This felling ended in 1735. One can imagine the forest landscape in 1735, twenty seed trees per hectare, standing over regrowth of seedlings and oak shoots aged from 1 to 50 years, not to mention the moorland of molinia or heather!
The forest was exhausted at the end of this period and no exploitation could take place for almost 40 years, because there were no stands that could be exploited.
Exploitation recommenced in 1779, with 6900 ha worked as coppice with standards, with 50 year rotation, then 40 year rotation in 1788. 3700 hectares in the very heart of the forest, between «Sologne and Marmande» were saved through this treatment and grown as high timber trees.
The first planning as timber forest dates from 1835, and led to the first regenerations in these stands, which were still very young at the time, by seedlings or by plantation (around 9800 hectares of moorland in 1832 according to the report by forest inspector Joseph Louis de Buffévent).
Successive planning provided for their gradual renewal over 175 years, in increasingly large stands, of which the Colbert timber stand is the last vestige. It is these stands that have marked the collective imagination and ensured the reputation of Tronçais forest which, over the course of the past century, produced large diameter fine grain oaks, found in no other French oak forest.
That is a summary of the history of Tronçais Forest, which owes its current appearance rather more to the forestry management of the Ecole Forestière de Nancy than to Colbert. The stands that made the forest’s reputation no longer survive except in the form of aging fragments in the managed biological reserve in the Colbert timber stand. Contrary to received opinion, there has never been so much old wood and such a good spread of ages as there are now, due to this long period of conversion into a uniform high forest.