The IGN publishes its inventory of forests and tells us that contrary to popular belief, the forest is increasing in area in Occitanie, as everywhere in France. The bad news is that she is showing signs of poor health. And that is not without consequences for humans.
Are the forests healthy? Are they losing surface area and diversity? What impact does their evolution have on humans? The IGN, forest watchdog and producer of national forestry statistics, publishes the results of the national forest inventory (IFN, annual measurement campaigns 2019-2023). This inventory allows for better knowledge and better monitoring of French forests, public and private, increasingly affected by climate change. It has been carried out since the 1960s, through permanent survey work, an inventory of trees, soils, plants and forest habitats thanks to around fifty agents throughout France.
In 20 years, forests have gained 800,000 hectares in Occitania
And our departments of the former Midi-Pyrénées have also been scrutinized – even if the area of the hills of the Garonne between Bordeaux and Toulouse is not very wooded, neither is the Gers. And oh surprise for the neophytes that we are, our forests are not losing surface area, on the contrary. In around forty years, in Occitania, we have gained nearly 800,000 hectares, from 2 million hectares in the 1980s to 2.8 million in 2024, almost the equivalent of the entire surface area of Aveyron or 68 times the size of Toulouse. How is this possible?
Nathalie Derrière, the head of the inventory results department at IGN details “the forest is increasing in area due to the abandonment of agricultural land, natural reforestation or man-made reforestation. The natural evolution of the land goes towards a forest, towards afforestation, there are first different plants which settle in, scrub then certain pioneer species and then we move from agricultural land to wasteland and little by little , there is an increasingly dense“.
Rising mortality and trees under stress
On the other hand, the forests are not doing well. “Tree mortality is increasing significantly. In the space of ten years, we have twice as many dead trees as we had before. We also notice that the trees are increasingly damaged, they have fewer leaves and lack branches. It’s a sign of suffering.” In Occitania, the chestnut tree is particularly affectedone in three is in poor condition.
It takes between 50 and 100 years to build a forest, the inventory is therefore there to observe, describe and provide information to ministries, managers and the wood industry which wants to know if in 30 years for example the sawmills established in Ariège will still have spruce to saw or whether we will have to look for it further or move on to something else.
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