Results from pathfinder projects

Halting the erosion of biodiversity in agricultural environments requires the development of approaches and tools that enable farmers and agricultural collectives to take ownership of this issue and manage it more effectively. The ADORE project developed a biodiversity management approach for farms that gave gave a free hand in deciding what they wanted to do to conserve/promote biodiversity, steering these projects with a “results-based approach”. However, the dissemination of this method could be limited by 1) the commitment of farmers or agricultural collectives to the approach and objectives of biodiversity conservation/restoration and 2) the choice of the most relevant indicators for monitoring the results of actions taken to conserve/restore biodiversity.

Faced with the erosion of biodiversity, public policies have set an ambitious agenda, as illustrated, for example, by France's national biodiversity strategy. This strategy sets out a plan for the protection and restoration of ecosystems, with the aim of establishing protected areas covering 30% of the country, including 10% of high-level protection. In this context, public environmental policies are reflected in increasingly diverse and sophisticated contractual tools, most of which have a direct or indirect impact on land ownership rights, which need to be documented empirically.

The forest ecosystems of Occitanie (France) are located at a biogeographical crossroad between Atlantic and Mediterranean climatic influences, making them and their associated biodiversity particularly vulnerable to climate change and its functional consequences for biocenoses. The conservation of biodiversity in natural ecosystems depends partly on the development of faster, less costly and non-lethal tools for monitoring and quantifying biodiversity. New monitoring tools can help to provide indicators of the resilience potential of forests to environmental change, which can be used to implement biodiversity-friendly forest management practices.

Retaining perennial habitat trees that have been spared from logging is recommended to promote forest biodiversity. Ongoing climate change is exposing these trees to increased stress (drought, heat waves, pests, and herbivores), leading to dieback, particularly in regeneration gaps. Managers are questioning the effectiveness of retention trees in these situations: can associated forest species fulfill their niche if the tree dies quickly?

Agroforestry systems (AFS) combine trees, crops and/or pastures in order to optimise agricultural production while improving the provision of ecosystem services. Their functioning is based on complex interactions between plant and soil subunits, the intensity of which depends closely on the spatial organisation of the system and the associated agricultural practices. Among the key processes governing these interactions, the nitrogen cycle plays a central role in plant productivity, soil fertility and the sustainability of AFAs.

Intraspecific diversity plays a major role in ecosystem functioning. However, it is strongly affected by human activities. For example, freshwater fish are subject to pressure from climate change, fishing, pollution and management practices such as restocking. These species support major ecosystem services, such as fish production, nutrient regulation and water quality. Changes in their intraspecific diversity could therefore have significant ecological and socio-economic consequences.

The MODIMIV project aims to model the relationships between microbial and plant diversity in multi-species agroecosystems, particularly grasslands, in order to improve the simulation of carbon (C) and nitrogen (N) flows and better synchronise nutrient supply and demand. The initial objective was to overcome the limitations of existing models, which often incorporate biodiversity in an implicit or simplified manner, by developing explicit and dynamic simulators capable of representing biotic interactions.

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. Existing models suffer from a lack of ecological realism, from a high level of complexity that makes them hardly usable for applied management problems, and from a relative disconnection from the needs of environmental managers. In other words, although these models have all the ingredients needed for becoming decision-making tools, they remain mainly restricted to the academic sphere and their results have little impact on management.

Numerous studies show the central role played by agricultural systems in the collapse of biodiversity. Assessing the performance of agricultural systems in terms of maintaining biodiversity is an essential step in supporting their agroecological transition. However, there are few predictive biodiversity indicators, particularly at the landscape level, which is nevertheless the most appropriate level for assessing the effect of agricultural systems on biodiversity (NIVA-Biodiversity is one such indicator).

The role of genetic diversity in maintaining species diversity and ecosystem functioning is now widely recognised. In the face of environmental change, this diversity contributes significantly to the resilience of ecosystems and the adaptive capacity of species. Integrating genetic diversity within species is therefore essential in order to implement management and conservation measures. The lakes and ponds of the Aquitaine coastline, ecosystems that are unique on a national and European scale, are home to significant plant biodiversity that is now seriously threatened