This text is part of the special section 100 years of Acfas
Floods, forest fires, droughts: if, to date, the natural imbalances caused by humans prove to be an indisputable scientific fact according to the Intergovernmental Panel on Climate Change (IPCC), we could not say as much a few decades ago. At Quebec, Pierre Dansereau is one of the first researchers to have measured the impact of humans on their environment.
The sky is gray in Percé. Pierre Dansereau stretches out laughing on the ground covered with horizontal juniper. He happily becomes one with the flora he describes with the wonder of a child. In this scene from the documentary A few reasons to hope, directed in 2001 by Fernand Dansereau, only his white hair and his ribbed face betray his 90 years. The work takes us back to the significant places of the scientist’s career, and his passion for nature is palpable there.
The latter was born during childhood, when the family went to Gaspésie for the summer holidays: “There were a few people around me who could decode the landscape, initiate me as best they could to what the escarpments, the beaches, the barachois, the bogs, confides the intellectual to the camera. My real vocation, which is the analysis of the entire landscape, what we later called ecosystems, germinated in my subconscious. »
This vocation, Dansereau first embraced it by obtaining his doctorate in plant taxonomy at the University of Geneva in 1939, then by collaborating with Brother Marie-Victorin at the Montreal Botanical Garden and teaching at the University of Montreal. (UdeM) and Michigan.
Ecology is then a fairly young science. “Ecologists were discovering what we now learn at school, they were trying to understand the exchanges of energy, the relationships between vegetation, animals, lakes, the sun”, explains René Audet, professor in the Department of Strategy , social and environmental responsibility from the University of Quebec in Montreal (UQAM).
It is in this context that the botanist Pierre Dansereau published in 1957 Biogeography: An Ecological Perspective, which states several laws governing the interactions between living beings, notably observed in the Laurentian maple stand. The work is one of the first to describe the human as an actor, a transformer of the natural environment, this one being at the time considered as a simple spectator, contextualizes René Audet.
“He brings humans into the discipline of ecology, he creates analysis grids to show how his impact can be measured in ecosystems, diagrams and maps”, specifies the sociologist.
In 1973 appears The land of men and the inner landscape, in which Dansereau calls for the modification of our lifestyles for the preservation of the planet, thus making itself the Quebec counterpart of the emerging environmentalist discourse, notably carried by Dennis Meadows, Barry Commoner or Paul R. Ehrlich. “He became a friend of the Greens, an activist who got involved in the movements and published in environmental newspapers”, mentions René Audet.
He introduces his concept of “joyful austerity”, pointing the finger at overconsumption, inviting his readers to lead a frugal existence out of joy of heart. His adage, “our failures are the failures of the imagination”, reveals his incredible faith in our ability to renew Western values and innovate to live in harmony with nature.
“Over time, Dansereau has shown itself to be more committed, denouncing pollution or the consequences of urban sprawl, but always with optimism,” underlines Pierre JH Richard, paleogeographer and professor in the Department of Geography at UdeM.
The legacy of Pierre Dansereau
In 1970, Pierre Dansereau led the environmental investigation of the future Mirabel airport which, according to many, would lay the foundations for current impact studies. In order to carry out the reports describing among other things the soils, the fauna, the flora, the profile of the inhabitants of the site, he questions the citizens, surrounds himself with engineers, geographers, geologists, psychiatrists.
“Dansereau is one of those researchers who have demonstrated the need for all environmental work to be as rigorous as possible, based on solid analyzes acquired in the field by experts from all walks of life pooling their knowledge », according to the professor in the Department of Sociology at UQAM Louise Vandelac. He would thus have contributed to making ecology an interdisciplinary science.
In this sense, he participates in the creation of a master’s degree, a doctorate and an institute in environmental sciences at UQAM, the first programs linking the human, social and natural disciplines in North America.
Died in 2011 shortly before his 100th birthday, Dansereau authored more than 600 scholarly texts and offered university courses on several continents. “You could say that he paved the way for a new generation of researchers and activists,” she concludes.