PhD projects results

In current practice, crop mixtures combine cereals and legumes to control weeds and recycle nitrogen. The various methodological approaches employed (experimentation, modelling, knowledge-sharing workshops, database analysis) proved to be highly complementary in the design of the EcosysteMIX prototype, a tool to assist in the design of species mixtures based on the functional approach.

SEINARIOS sheds light on the role of connectivity in the composition of river fish communities, as well as on the influence of management and climate change on future river ecosystems. It provides practical guidance for future management and new methodologies for assessing connectivity within river networks and integrating it into modelling approaches for the distribution of river fish, whilst evaluating the significance of climate change and land-use management on the conservation of fish species.

The innovative analytical approach (SKR) developed in PRAIRIES MC CC, combined with a large dataset on permanent grasslands in the Massif Central, has shown that the dynamics of trait distributions depend on management practices. In unfertilised grasslands, trait distributions are remarkably even and stable. Ceasing fertilisation allows for the long-term recruitment of a rich and diverse grassland flora. The SKR approach can help to design management methods suited to the conservation and restoration of biodiversity, as well as to the maintenance of ecosystem multifunctionality.

SYNBIOTOX, through ecological and ecotoxicological monitoring of a pilot constructed wetland (CW) located in Seine-et-Marne, demonstrates that the risk posed by agricultural contaminant flows within the CW is significant for amphibians, and that negative behavioural and ecological effects are exerted on aquatic fauna. This thesis provides a better understanding of the potential impacts of agricultural contaminant flows on aquatic fauna in constructed wetlands.

The isoetid communities of the oligotrophic coastal lakes of Aquitaine, ecosystems unique in Europe, are under serious threat. The microsatellite markers developed by ISOTEIDES to characterize genetic diversity and analyze the relative contribution of spatial and environmental processes to the structuring of taxonomic and genetic diversity lead to recommendations for the conservation management of these lakes at both the local and regional levels.

The model of the Camargue delta’s functioning (MAELIA-Delta), developed in this thesis and tested under various scenarios, demonstrates the central role of water management in balancing agricultural activities, soil salinization, and the preservation of natural habitats in the Camargue. It provides a body of knowledge that stakeholders can use to design a more integrated management approach for the delta, aimed at reconciling agriculture and ecosystem conservation.