Interaction networks

Agroforestry, broadly defined as the presence of trees in agricultural landscapes, is an example of mixed farming that increases "planned biodiversity". Thanks to their perennial structures, these trees create a microclimate that varies over time, leading to changes in the associated biodiversity and the activity of organisms through habitat diversification. However, few studies have looked at the effects of agroforestry on soil organisms and the functions they perform.

Biodiversity is the baseline of all ecosystem services and thus represents an essential supporting service. The lakes and ponds of the Aquitaine coastline are unique ecosystems at both the national and European levels. They host significant biological diversity, especially from a plant perspective, but are currently under severe threat. While the taxonomic diversity of these communities is well-known, the knowledge of their genetic diversity is currently non-existent. Improving this knowledge however appears essential for better management of these ecosystems, particularly for their endangered species.

The BIOC@PT project (Automatic Forest Biodiversity Sensors) is exploring new ways of acquiring biodiversity data that are faster and less costly than traditional morphological identification of species in the laboratory.

As a result of changes in farming practices, climate change and the increasing number of beekeepers and apiaries, tensions are emerging around floral resources, i.e. the nectar and pollen used by the bees. Long considered to be unlimited, these floral resources seem to be the object of a competition, both inter-specific between wild and domestic bees and intra-specific between domestic bees. This leads us to consider these floral resources as a common good to be managed collectively, involving not only beekeepers and biodiversity managers, but also the farmers who shape these landscapes and whose practices influence the availability of floral resources.

There are over 20,000 species of wild bees in the world and close to 1,000 in France. This great diversity of species, all differing in terms of morphology, mobility, phenology, nesting sites and more importantly floral preference, is essential for the pollination of a wide variety of wild and cultivated plants. The health of bee populations is threatened by many factors such as intensive agricultural practices and land management.

Studying the dynamics of plant biodiversity, from its emergence to its dispersal by water. Agricultural intensification has degraded ecosystems, and it is now necessary to take greater account of the role of biodiversity in agrosystems and its importance for ecosystem services provision. For the past two decades, cultivators in vineyards have been improving their sustainable management practices, developing a vegetation cover inside inter-rows to limit soil erosion, and an extensive management of plot edges and networks of ditches. These practices support the development of a spontaneous vegetation cover, a source of numerous ecosystem services including for example runoff regulation, water erosion mitigation and organic pollutants retention.  This is a major challenge, particularly in Mediterranean vineyards, where climate change is likely to increase the frequency of intense rainfall.

The management of invasive alien species (IAS) is a complex problem requiring interdisciplinary approaches that combine ecology and economics. Bio-economic decision-making tools are still underdeveloped.

Analyse the role of black woodpecker cavities in the conservation of forest species. Assessing the conservation state of forest habitats is mainly based on indirect methods. For species at stake, the contribution of forest structural elements to population remains poorly known, and, therefore, the link between natural habitat state of conservation and species is not evident.

The increasing use of various kinds of plastics leads to the accumulation and long-term storage of microplastics (MP) in soils. There is a growing scientific literature linking the presence of MP and the consequences for soil organisms that perform essential ecological functions. However, for the most part, these are ecotoxicological approaches through effects on certain organisms studied separately (microorganisms, micro-, macrofauna and plants), without addressing ecotoxicity issues. Moreover, in agricultural soils, the presence of MP may be due to inputs via amendments with organic matrices and their impact on the biological functioning of soils is then little documented.

Some of the agricultural contaminants (pesticides, nitrogen) spread on cultivated soils reach the hydrosphere through agricultural drainage (1) with proven consequences on aquatic ecosystems and their functions. Constructed wetlands are designed to break down nitrates and certain pesticides through natural purification features. Nevertheless, they constitute potential reservoirs of contaminants likely to impact the wild species they shelter by acting as ecological traps.