Résumé
Vegetation has been widely used on geotechnical engineering structures (e.g., embankments) associated with infrastructures and industrial sites (e.g., terrestrial transport, quarries, mines and urban spaces), as an effective tool against soil erosion and shallow landslides hazards. Besides such a protective role, sustainable vegetation management on these engineering structures is increasingly desired for favoring multiple ecosystem services, such as enhancing aesthetic value, promoting public safety, biodiversity conservation and climate change mitigation via carbon sequestration. In this context, Valorhiz (URL: http://valorhiz.com/fr) developed an innovative solution (TalVeg®) that comprises a Decision Support System (DSS). This DSS allows designing and optimizing multi-functional ecosystems considering managers and customers’ requirements (considering e.g., maintenance costs, biodiversity and/or ecosystem services enhancement). The DSS acts at the bio-technosol scale and aids towards the selection of plant species and associated microorganisms. For these purposes, TalVeg® innovation is composed of three technological components:- Databases of plant, soil and symbiotic micro-organisms- Mathematical models that simulate plant and water dynamics within soil according to climate scenari- Computation of biodiversity and ecosystem functionsMethodsVALORHIZ started to implement, in 2015, several pilot sites in railways, highways, quarries and ski slope contexts. Several experimental modalities (with contrasted seed mixes and microorganism inocula) were set up on these sites to test the effect of TalVeg® components on vegetation success (rapid and perennial development of a dense plant cover) and soil functions (soil structural stability, soil shrinkage and water retention curves).Results & DiscussionThe dynamics of plant communities, soil function and biodiversity and their interactions, will be monitored at all sites for over 3 years. The preliminary results (after 6 months) will be presented with an overview of how doing best to manage novel ecosystems with regard to soil erosion mitigation and slope stability maintenance. Potential pathways of incorporating multi-functionality to the dominant function of natural hazard mitigation will also be discussed. This study enables us to gain a better understanding of soil-vegetation interactions in a context of ecological engineering, open new perspectives with regard to the management of degraded ecosystems, and enhance multiple ecosystem services