Program

Who are we?

The SAGID+ Industrial Chair, led by the ERPI laboratory at the University of Lorraine, is conducted in partnership with the industrial group ACTIBAC and the Métropole du Grand Nancy.

The project aims to generate knowledge about roadsides and their management practices in order to assess the externalities associated with these activities.

The purpose of the present consultation is to evaluate the effects of management practices on five studied ecosystem services: water regulation, soil health, biodiversity conservation, and resilience to fire risk and the spread of invasive plant species.

The assessment is based on expert judgment: the practices are compared with one another, independently for each service, to measure their relative impact. All practices are organized within a taxonomy developed in collaboration with managers.

Contact us by email: contact@sagid.org

Methodology

Simplifying assumptions:

A maintenance policy can be broken down into a list of practices. The gain associated with the studied ecosystem services is considered additive. This approach makes it possible to compare the relative effectiveness of different actions by referring to an “average context” of the roadside socio-ecosystem.

The assumptions of independence between practices apply only during the initial assessment phase; they are then relaxed in complementary assessments, which respectively explore the interactions between practices and the influence of the environmental context.

The ecosystem services studied were defined to provide a framework for analysis, but they are considered in a broad sense so as to preserve the diversity of disciplinary approaches and the richness of expert perspectives. This approach aims to maintain the complementarity of the expertise involved. Indeed, a definition that is too narrow could:

• Reduce or exclude certain aspects of ecosystem services.
• Constrain experts to adopt an analytical framework that does not always reflect their own knowledge and experience.

Consensus around the notion of what is “favorable to an ecosystem service” is built progressively and organically within the scientific community of experts concerned, across all disciplines and backgrounds.

 

‘Practice Taxonomy’ Approach

Benefits of a practice list:

Collective intelligence – The actions are written by those who implement them and evaluated by those who study them. This approach fosters interdisciplinary cooperation and facilitates the involvement of the various communities concerned with the socio-ecosystem in question. It encourages collaborative work among managers, researchers, and territorial stakeholders.

Accessibility – The tool is easy to use, open-access, and simple to understand, explain, and adapt. It enables the formulation of clear, visible, and verifiable improvement objectives without requiring costly measurement systems. This flexibility allows the integration of small-scale projects while ensuring their coherence with broader territorial dynamics.

Implementation

Each practice is broken down into 3 to 5 alternatives, labeled from A to E (at most). The comparisons focus on improvement factors rather than on potential losses. The “minimum” level of each scale serves as the common reference point, defined as the alternative providing no or the least gain for the ecosystem service under study. Conversely, the “maximum” level represents the optimal implementation of the practice, aiming to best promote the studied ecosystem service while respecting technical and regulatory constraints.

This breakdown into alternatives supports the progressive implementation of actions favorable to the targeted service, while facilitating their integration into broader territorial strategies and objectives.

Taxonomy

 This taxonomy was developed based on feedback (survey responses) and active contributions (guided interviews, validation workshops) from road network managers.

‘Expert Majority Voting’ Approach

Expert Judgment:

To assess the influence of a wide range of roadside maintenance practices on the identified ecosystem services, as well as the interactions between practices and the effects of the environmental context, expert judgment was employed. The informed intuitions of these specialists help compensate for the limitations and uncertainties inherent to field measurements, which are often challenging due to the diversity of conditions and the complexity of possible combinations. In this context, the assessment does not rely on numerical values derived from in vivo experiments, but rather on the degree of agreement among evaluations provided by a complementary community of experts.

Thus, the ecosystem services are not approached through isolated quantitative indicators, but through a synthesis of expertise and accumulated knowledge from the participants.

Relative Positioning

The exercise is based on a comparative positioning of the different management alternatives relative to one another. It is neither relevant nor realistic to assign an absolute score to ecosystem services, especially since they are not strictly defined or measurable. However, it is possible to rank the practices by expressing their differences in relative effectiveness with respect to the ecosystem service under study.

A quantitative result thus emerges from measuring the differences in positioning between the alternatives. This approach allows the relative influence of practices on each ecosystem service to be assessed in the specific context of roadsides, without claiming a universal measure or one that can be applied outside the scope of the study: the ecosystem service provided by the roadside.

Fundings

The SAGID+ project is co-funded by the European Union through the European Regional Development Fund with €409,500, by the ACTIBAC group, and by the Métropole du Grand Nancy. It contributes to the collective ambition “Des Hommes et Des Arbres, les racines de demain” (Men and Trees, the Roots of Tomorrow), which has been awarded the Territory of Innovation label. The project has also received the Solar Impulse Efficient Solution Label.  

Acknowledgements

Thanks to the team who made the methodological development of the platform for this survey possible: Romain Julliard, Flavie Thévenard, Arthur Pivin, Matthias Gaboriau, Louise Dupuis, Hélène Soubelet, Aurélie Delavaud, Denis Couvet, Colin Fontaine, and to the MOSAIC team at MNHN who designed and developed it (as well as to all those who participated in the design workshops, the taxonomy of practices, and our discussions).

Contact: MOSAIC – mosaic@mnhn.fr (Methods and Tools for Participatory Sciences), under the joint supervision of MNHN and Sorbonne University.

Thanks also to all the experts who generously gave their time—a precious resource—to participate in the evaluation of the taxonomies and contribute to the success of our project.

Contact us: contact@sagid.org