The basket desperately empty, the penknife still clean… This fall, the picking parties turn most of the time into a simple stroll, or even a downright depressing trip, for mushroom lovers. Almost no porcini mushrooms, much less blood sugar to eat, to transform into an omelet or to keep in jars, the fault of the drought which lasts and continues.
While some continue their rain dance with the secret hope of a providential surge, specialists are measuring the impact of global warming on the plant cycle. On the Côte d’Azur, Jean-Louis Raffaghello, head of the mycology section of ANNAM, the Association of Naturalists of Nice and the Alpes-Maritimes, takes stock of the situation.
Mushrooms, can we still find some?
Currently, back home, in the Alpes-Maritimes, there is practically nothing on the coast and really not much in the mountains either. You have to walk a lot to hope to find a few specimens. It’s very dry. Everywhere. And the observation is the same elsewhere. I know that in Isère or in the Pyrenees, for example, it is also very complicated this year. It is perhaps only in the north of France where there are still extraordinary outbreaks of mushrooms because it has rained a lot.
Is it the same for porcini mushrooms?
Unfortunately it’s the same problem. If it’s too dry, they won’t come out. And right now, that’s the case. In fact, mushrooms are essentially invisible, almost everything happens underground with the mycelium, a network of filaments that can fetch water very deep and which also brings it to the roots of trees. They are in symbiosis. This mycelium provides the vegetation with water and recovers nutrients to develop. But for there to be fruiting, that is to say for a mushroom to grow in the open air, there must be enough water. And this year is the perfect example: it’s missing. The fact that there is nothing on the surface is a sign that the mycelium is suffering. If there were to be heavy rains, we could still have an explosion of mushrooms, but the further we go in time, the greater the risk of frost becomes.
Are there any species that seem more resistant to drought?
It’s not really obvious. But I can tell you about what we are currently observing in the Alpes-Maritimes department. While we have hardly seen any Lactarius, the “sanguinians”, nor Petits-gris, and even less Rosés-des-prés, in the mountains, we still come across a few Suillus, mushrooms which are precisely mixed to the trees, the larch trees, the fir trees. These are still there, but in smaller quantities.
With all of this, what advice would you give to pickers who are not yet totally discouraged this year?
It’s simple, the key is water. Always water. So, you have to go to the parts that are more in the ubac, that is to say in the shade, where humidity can remain. In the valleys, on the northern slopes and in areas that can serve as reservoirs, we can possibly hope to find them. In direct sunlight, it’s not even worth thinking about.
More generally, is global warming already having an observable impact on the distribution of fungi?
We have the impression that certain mushrooms tend to rise in altitude, because of the heat. There have been several observations that confirm this. Three or four years ago, for example, we saw an extraordinary surge of Oronges [l’Amanite des Césars] in a high area, where it was very unusual to see them.
Will we still see mushrooms in 2050?
Mushrooms know how to adapt, but to a certain extent. We will still find some, but much less. For me, that’s a certainty.