Published on 13 May 2019
Fleurs - champ - biodiversité

Five questions to Jane Lecomte, director of the Ecology, Systematics and Evolution laboratory

The Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES), devoted to the study of "erosion of the living", has just concluded its seventh plenary session in Paris. It is preparing a new assessment of the global state of biodiversity.

Jane Lecomte, Professor at Paris-Sud University and director of the Ecology, Systematics and Evolution Laboratory (UPSud, CNRS, AgroParisTech), presents the findings made by IPBES and the work of Université Paris-Saclay in this field.

1. What is the role of IPBES?

IPBES, established in 2012, provides independent scientific expertise to assist governments in any biodiversity-related decision. It is a bit like the IPCC for biodiversity. She has just presented a three-year work involving several hundred experts on the current state of biodiversity. The previous inventory had been the subject of a first report in 2005.

2. What are the main findings presented in this report?

The trends are the same as in 2005 while being more alarming. There is an unprecedented rate of species extinction that is accelerating. Of the 8 million known species, one million of them are threatened, whether animal or plant. More than 40% of amphibians, 33% of corals and a quarter of mammals! There is indeed a significant decline in numbers of many populations of species, which foreshadows in the long term a rapid extinction.

The causes of these extinctions are anthropogenic. The first is related to the change of land use, particularly related to agriculture, but also to the sea. It is striking that 75% of the land surface, apart from a few deserts, has been transformed by the sea. 'man. Resource exploitation, like intensive fishing, comes second. The third cause, and this is new, is linked to climate change, which shows that the issues of climate and biodiversity overlap. The big difference however lies in the temporalities of the different phenomena: we can have immediate actions impacting the local biodiversity whereas the climate variations are global and in the long term. Then, in the fifth and sixth cause of extinction, we find the pollution and the introduction of invasive alien species. There are also indirect causes such as population growth and increased consumption of biological resources by all and unsustainable.

3. Are there French specificities?

France has a special responsibility because it is home to 10% of the world's biodiversity, especially with its 19,000 endemic species present in its overseas territories. We are also one of the ten countries with the largest number of endangered species. In metropolitan France, the artificialisation of soils due to the extension of urban areas, agricultural intensification and the very significant reduction of wetlands have major impacts on biodiversity. Only 22% of natural habitats (meadows, marshes, dunes ...) are in a good state of conservation.

4. Are there any specific works done at the Université Paris-Saclay in this area?

At ESE, Paul Leadley is France's representative at IPBES and we have two other report writers, Franck Courchamp and Céline Bellard.

We conduct research, in France and abroad, on the impact of anthropogenic disturbances (climate change, environmental pollution, invasive species) on the dynamics of populations and communities and their risk of extinction. We also study the effects of climate change on the functioning of forest ecosystems and their response to these changes.

We are working to provide solutions to this erosion of life by studying agricultural practices and the structuring of agricultural landscapes that favor biodiversity. In an even wider context, we are considering the transformation of socio-ecosystems because, to curb the erosion of biodiversity, new public policies must be put in place at national and international level. We are also developing an ethical vision of the conservation of living organisms that intends to let biodiversity entities continue their evolutionary trajectory beyond our own interests.

Of course, there are other teams at Paris-Saclay University, such as the Tara Oceans expedition, which has collected and analyzed in depth 35,000 samples of marine plankton.

5. What is the Institute Ecology, Diversity, Evolution of Life (IDEEV) which will be housed in a building currently under construction on the Saclay plateau?

The IDEEV (Diversity Institute, Ecology and Evolution of the Living) is a research federation composed of three founding research units: EGCE (Evolution, Genomes, Behavior and Ecology), GQE (Quantitative Genetics and Evolution - The Moulon) and our unit , ESE. Our research in these three laboratories focuses on biodiversity, which led us to meet in a building that should be ready to welcome us in 2021-2022. This proximity of agricultural experimental lands but also of the natural agricultural and forest protection area on the Saclay plateau will offer us new study areas for agroecology research with other scientific partners of Paris-Saclay University.