Anthropogenic and degraded ecosystems are characterized by contamination events, which can be historical, complex and in very close proximity to the human population. In these contexts, it is necessary to have a large range of complementary approaches to improve knowledge about contamination and the fate of pollutants and their dispersion in ecosystems. The aim is to improve the functionality of degraded environments and to prevent and reduce environmental and health risks. This work responds to recent and important societal expectations, as well as to economic issues in urban, agricultural and forest environments.
To meet these scientific and societal challenges, the research of ER 4 focuses on diagnosing and assessing the state of ecosystems, defining new indicators of exposure and/or effects of pollutants, managing biodiversity, and ecological engineering. The problem also requires the development of a multi-scale approach, from the molecular to the landscape level, and is based on experiments in microcosms, mesocosms, and in situ. approche multi-échelle, du moléculaire au paysage et s’appuie sur des expérimentations en microcosmes, en mésocosmes, en sites ateliers et in situ.
The team's fields of expertise are varied and complementary :
- characterization and analysis of soils and sediments in agricultural, urban and forest environments,
- taxonomic and functional characterization of soil fungal, floristic and faunistic communities (meso and macrofauna),
- measurement of biological activities in soils and of biomarkers of toxicity (macrofauna and plants),
- assessment of the impregnation of vegetation (natural and cultivated) and soil fauna by pollutants (inorganic and organic pollutants),
- determination of functional traits,
- plant and fungal biomonitoring of air quality,
- assessment of population exposure in relation to the ingestion and inhalation of contaminated soil particles and dust, consumption of foodstuffs produced on polluted sites,
- the study of territorial health, social and environmental inequalities through statistical and geostatistical analyses.
The research of the ER4 are structured around 4 main topics :
This topic aims to assess the functioning of degraded terrestrial ecosystems at different scales of observation. The approach is based on :
- monitoring and bioindication of ecosystems, taking into account their degree of contamination, changes in territories and their uses, and climate change,
- characterisation of the interactions between various compartments of biodiversity,
- the definition of environmental quality indices, in interaction with natural environment managers and relevant organizations,
- a contribution to establishing links between the toxic effects observed on soil organisms, via biomarkers, and those observed on populations and ecosystems (functional and biofunctional indices).
One aim is to provide information on the functioning of ecosystems and their evolution through the cross-analysis of data from the characterization of environments (soil, air, water, pedo-fauna, plants, fungi) and their uses. The approach is primarily based on the use of tools such as geomatics, statistical analysis, bioinformatics and modelling.
This research focuses on the study of the behaviour of pollutants in soils by considering physico-chemical and biological parameters and the nature and degree of evolution of organic matter. It also aims to develop a mechanistic approach to the interactions between mixed pollutants and plant and animal organisms, through the joint observation of the bioavailability of pollutants and the functioning of organisms (toxicology, life traits).
Regarding the rise of multiple contaminants, it is necessary to amplify the study of emerging pollutant transfer (nanoparticles), to develop that of organic pollutants (pesticides, particularly in urban soils) and to integrate new concerns (such as micro-plastics).
In addition to traditional taxonomic tools, this research aims to develop, using molecular tools, the capacity to identify soil organisms (fauna and fungi). The approach also defines the relationships between the responses of biomarkers and life traits while at the same time considering the variability in the expression of biomarkers or batteries of biomarkers in model organisms. The development of diagnostic tools, ecotoxicological monitoring, assessment and characterization of biodiversity should make it possible to establish recommendations in terms of the diagnosis and management of disturbed ecosystems.
The first challenge is to identify and understand the mechanisms of the transfer of pollutants to humans, in order to develop realistic methods for measuring their bioaccessibility and to specify the exposure routes. This work uses statistical and geostatistical tools to analyze the links between health and the environment at the territorial level, based on the development of aggregate, composite or integrated indices. When confronted with socio-economic indicators, the linking of environment-health data can highlight territorial inequalities and propose decision support tools for managers.