Many studies on the impact of current climate change on biodiversity observe or predict major changes in the composition, functioning of communities and the dynamics (speciation - extinction) of species. Research in this scientific field aims to study the short and long term effects, as well as the past effects, of climate change on biodiversity in terrestrial and marine environments, with a particular focus on biological and ecological models taken in the region. Hauts-de-France.

For the next five years, research in this scientific field will always be organized along two axes:

• Axis 1 "Environmental pollution and effects on organisms and ecosystems" will integrate collaborations relating to the study of the distribution of pollutants within terrestrial ecosystems (freshwater or estuarine environment with particular attention to the level solid / liquid interfaces of rivers and their mouths), and the impact of these pollutants on organisms and communities as well as their resilience. Regarding the impact of pollutants on organisms, a major effort will be made to exploit the availability of whole genome sequences, high throughput sequencing methodologies, and significant internal skills for the use of bio tools -performance computing, in order to identify the genes and / or genomic regions involved in the adaptation to these pollutants. Experimental approaches under controlled conditions will be carried out in particular on the evolution of tolerance to metallic trace elements in plants, and on the impact of variable micro-climatic conditions but also of the load of pollutants on the dynamics of wildlife communities. of the soil (especially the mesofauna) and their life traits. In fact, soil invertebrates play a major role in the dynamics of ecosystems, in particular through their litter degradation action which allows nutrients to return to the soil.
• Axis 2 "Climate change and impact on ecosystems and biodiversity" concerns on the one hand the characterization of climate change and its consequences on the properties of the abiotic environment (soil, water and sediment), and on the other hand, the study of patterns and processes involved in the dynamics of biodiversity, focusing on the relationship with climate change. The strategic orientation is to develop on the one hand approaches to modeling the dynamics of biodiversity in relation to climate change, and on the other hand the integration of data from direct observations (field work or experiments in greenhouses or laboratory) or indirect (inferences from molecular data).

A new section concerns the study of interactions between plants and pollinators as witnesses to the impact of climate change on the functioning of communities. Indeed, the availability of floral resources can be altered by climate change and the modification of land use; likewise, climatic changes in synergy with other anthropogenic forcings such as air pollution are likely to affect the survival of pollinator communities. The health and ecological impacts during extreme climatic events can be major, especially in an urban environment. This component will therefore aim to assess the potential impacts of climate change along an urbanization gradient and therefore a possible thermal gradient (heat island effect) and anthropization on the networks of mutual plants / pollinators.

Another component concerns the study of adaptation mechanisms at the scale of individual species through (1) the analysis of the immunocompetence of pollinating species of the genus Bombus along an urban gradient, using here the immunocompetence as a biomarker of sensitivity to environmental changes (direct observations and experimental approaches), and (2) exploring the link between the reproductive system of plant species and their sensitivity to anthropogenic changes (experimental approaches and inferences from data molecular).

A third part concerns the study of the impact of climate change on the dynamics of biodiversity through the study of the speciation process. Indeed, the diversity measured by the number of current species is the result of a dynamic which combines both the processes at the origin of new species (speciation events) and other processes reducing this number (the extinctions). Contemporary extinction rates measured by the reduction in the number of species or by the current reduction in population sizes appear to be high in plants and animals. If the factors responsible for extinctions begin to be well defined, our knowledge of the dynamics of speciation is more embryonic, preventing us from perceiving the long-term consequences of the global changes currently encountered. The objective of this component therefore consists of exploring the contributions of genomic, geographic and environmental factors to the appearance of new species. These factors will be studied at the different evolutionary time scales where the speciation process takes place, again combining various approaches.

IRePSE AAPs in this scientific field may be linked to WP3, 4 and 5 of CPER CLIMIBIO and allow to continue the collaborations initiated or to develop new ones in view of the advances made in the framework of CLIMIBIO. This part of the program is dedicated to the integrated study of the impacts of ongoing climate change and other anthropogenic forcings on biodiversity, human health, and socio-ecosystems.

Animation :

• Pascal Touzet (EEP)
• Baghdad Oudanne (LASIRE)
• Sébastien Lemière (LGCgE)