Two and a half years ago, the mayor of Paris Anne Hidalgo promised to plant 170,000 trees in the capital. A few days before the planting season, where are we at with this judged bet? untenable ” Where ” impossible »? In communication that it must read in the Council of Paris this Thursday or Friday, the town hall announces that it has planted, since 2020, “38,550 additional trees”. Figures disputed by associations, while the plan is the subject of criticism on the right or among environmentalists.
First thing to know: the majority of the trees planted by the city were in the woods and on the embankments of the ring road. Of the 38,000 and some trees, there are actually only 8,000 intramural trees. For this winter, the town hall promises 1,000 new trees in more than 70 streets of Paris, in particular place du Colonel Bourgouin (12th) where 38 trees will be planted and rue Harpignies (20th), which should receive 14 trees. 7,000 new trees will be planted in the woods and more than 11,000 on the embankments.
Mostly forest plants, not trees
But above all, among these trees, there are trees that are between 10 and 12 years old, and simple forest plants. According to the vegetation assistant Christophe Najdovski, the trees planted in the woods or on the embankments include a ratio of 20% young trees and 80% forest seedlings. “We will not have 170,000 trees in the end, when we plant forests there is a natural selection that takes place”, recognizes the deputy, who admits that it is mostly plantations and not trees , unlike the communication made to the Council of Paris Where in the press. In the end, of the 21,000 new trees planted this winter, Christophe Najdovski admits 18,000 “plantations”.
Exactly how many will survive? Hard to say, but according to Christine Nedelec, president of France Nature Environnement Ile-de-France, if it comes to plantations inspired by the Miyawaki method, “very quickly you will only have one tree out of 100 that will grow “. “An adult tree is between 25 and 33 m2, but the Miyawaki method consists of putting three feet of trees per square meter. They don’t have room to grow. There is 99% loss at age 50. It’s a bit like saying that a nail is comparable to the Eiffel Tower. Between an acorn that has just sprouted and a 60 ton tree, there is a huge difference. The town hall uses this method to artificially inflate the figures, ”adds Tangi Le Dantec, co-founder of Aux Arbres citoyen.
A study conducted in Europe on the “Miyawaki method” reported 61-84% tree mortality 12 years after planting. The deputy mayor of Paris specifies, however, that not all forest seedlings are planted according to the Miyawaki method: “Forest seedlings can be planted using other methods, with less density. »
Defend old trees
Above all, for Christine Nedelec, these figures actually have little meaning, because planting trees appears to be less of a priority than protecting those who are already there. “It’s stupid to brace ourselves on stories of accounts, what we would like is to limit felling, because what counts in trees is the leaf area, that’s why we defend the old trees, which have more surface area, and which have managed to acclimatize, and have a better chance of surviving”, believes Christine Nedelec.
“There is no point in planting thousands of trees, and since there is no space, the priority is to protect the trees in place”, agrees Tangi Le Dantec, for whom it is impossible to plant 170,000 trees in Paris, which would occupy “a total area of open ground equivalent… to the 17th arrondissement in its entirety”.
No financing plan
On the environmental side, the results of the tree plan “leaves a little unsatisfied”. Chloé Sagaspe, vice-president of the Environment commission at the Council of Paris, regrets that there is no detailed plan for each district of the plantations, and no information on the urban forests promised by the town hall of Paris, apart from that Catalonia Square, where work has begun, and where we learn that 400 trees will be planted there. “What about the forest on the forecourt of the town hall? Project in the 12th? To date, we have no visibility, and still no financing plan, worries the elected representative of the group Les Écologistes. It’s good to vote for ambitious plans but we have to give ourselves the means, and for the moment we have no information on the recruitment of personnel in the management of green spaces. »
“Place du Colonel Fabien, the consultation will start soon. And town hall square, it’s more complex, we are at the study stage, ”answers Christophe Najdovski. Far from the initial dream announced in the Sunday newspaper : a “hundred” of urban mini-forests.