Jean-Paul Metzger: The ecologist in the landscape

Accomplished scientists fall into two categories: those who perch in their ivory towers, and those who share their passion for research over a coffee table. Jean-Paul Metzger, professor at the University of São Paulo, belongs to the latter. His innovative thesis on the fragmentation of tropical forests quickly propelled him into the ranks of recognized ecologists. The theme was still new when he obtained his doctorate in 1995, but it was to become very fashionable, and his work became a benchmark for the notions of connectivity and ecological corridors. Indeed, he was one of the first to document how landscape fragmentation and the isolation of natural areas - due to human activities - led to a loss of biodiversity. In particular, it is impossible for species to recolonize isolated areas. "The aim was not only to record the loss of individuals and species, but also to understand how landscapes influence biodiversity and how to maintain or restore it", explains the researcher.

Jean-Paul Metzger fell into the field of landscape ecology while pursuing a DESS (post-graduate diploma) integrated into a UNESCO Chair and linked to the Institut d'Agronomie de Paris, the University of Toulouse and the University of Montpellier. For the young biologist, "landscape ecology, satellite imagery, all that was very new". When he came to live in France for the first time, the Franco-Brazilian student had no idea that he would go on to do research after his degree in regional planning. But, against all expectations, the academic world was easier to join than the job market. " In Brazil, the early 1990s were marked by the crisis under Fernando Collor's government. I had no job prospects. But I did find Brazilian funding to continue my thesis," recounts the scientist. Enrolled in Toulouse, he did his thesis on the Atlantic Forest, a tropical forest that runs along the entire Brazilian coast: "I became passionate about my subject, and my taste for research came from doing it". And the academic world paid him back in spades, as he immediately landed a job at the University of São Paulo at the age of 31.

Rain gardens

Jean-Paul Metzger's interest in human impacts on ecosystems has been followed by an interest in the services that ecosystems provide to humans. In other words, ecosystem services, an approach to the economic evaluation of biodiversity that took on a major role in ecology in the 2000s. He works on coffee crops, which cannot do without pollinators, pollination being an indispensable service provided by bees to crops. Always in touch with the scientific notions of the moment, the biologist is now working on nature-based solutions and the notion of One Health, the latest avatars of research to remind humans that they need to learn to live with the rest of the living world. He is particularly interested in science-society issues. In São Paulo, he brings together a team of around a hundred people, including researchers, activists and local officials, to co-create solutions to the environmental problems of the state of São Paulo.

The whole team works according to the knowledge synthesis approach, a participatory approach that relies on the collective to draw from the analysis of available data new avenues of research and practical answers to the problems posed. One of the proposals that emerged from this work to improve the quality of life of city dwellers and their city's resilience to climate change is the installation of new rain gardens, urban green spaces that capture runoff water. "These mini-water retention zones reduce the risk of flooding. Vegetation also provides shade and coolness in a city where temperatures are currently soaring to 40°C, and filters pollution. But it's also the quality of the landscape and the beauty of the surroundings that help to improve mental health. The positive psychological effect of living near parks on city dwellers is now recognized by numerous scientific studies.

Scenic beauty and urban health

Mobilized around the São Paulo state climate plan, another proposal emerged to reconcile adaptation and mitigation to climate change. Locate afforestation projects to capture carbon on the outskirts of cities, as restoring peri-urban environments, particularly in areas at risk of flooding and landslides, has an immediate beneficial effect for local residents. "In particular, this can prevent the installation of favelas in sloping areas or flood plains, where landslides and flooding represent a life-threatening hazard", explains Jean-Paul Metzger, who is decidedly concerned by town and country planning.

And what about his coming to France at the end of 2023? The opportunity offered by UM's MAK'IT (Montpellier Advanced Knowledge Institute on Transitions) program to spend three months in Montpellier piqued his interest in joining a recognized scientific community in tropical ecology and agronomy. But in the end, it was mainly at the Centre de synthèse et d'analyse sur la biodiversité (Cesab) - FRB's flagship program - that the researcher was able to start real collaborations. He also left behind a Brazilian doctoral student, Douglas Cirino, who is taking advantage of the analysis tools developed by Cesab to further his research into the links between scenic beauty and urban health. For his part, the proximity of the Pic Saint-Loup and the Montpellier hinterland has greatly contributed to his well-being, far from a megalopolis of over 12 million Paulistanos.