Flagship project 5: Model integration and multi-scale modelling in SES.       Coordinators: Pierre-Alain JAYET (Economie Publique), Paul LEADLEY (ESE), Benjamin LOUBET (ECOSYS) & Olivier MARTIN (GQE-Le Moulon)   

This project has three objectives related to guidance for research within BASC and resolving outstanding issues in developing and applying complex models of SES:

♦ identify all the models available within BASC, their users and people responsible for their development;

♦ integrate models across disciplines by constructing a conceptual framework for interdisciplinary SES models and developing tools for coupling existing models;

♦ use novel conceptual, mathematical and computational tools to tackle the challenges of multi-scale modelling and study propagation of uncertainty in these models.

Developing dynamically-coupled SES models

One of the objectives of the project is to study SES through coupling of models describing the following components: i) climate, atmosphere and hydrosphere, ii) ecosystem functioning and biodiversity, and iii) economics, public policies and land management and use. Two spatial scales will be favored, due to current work undertaken within BASC labs: i) lanscape scale, covering a few km², and ii) regional scale, from 10 000 km² (≈ territorial scale) to several millions km² (≈ national to subcontinental scales).

Models developed within BASC enable us to address innovative scientific questions which tackle the complexity of socio-ecosystems through the coupling, whether dynamic or not, of models of agricultural and non-agricultural systems functioning (eg. CERES-EGC, STICS, ORCHIDEE, CASTANEA…), climate/atmosphere/hydrosphere models (eg. MDz, MORCE-WRF, INCA, Chimère, Nitroscape...), and economics / public policies / land management and use (eg. AROPAj agroeconomic model, economotric models...). Outputs of these coupled models should help meet ecological, economic and environmental challenges.

Developping a conceptual and methodological framework to deal with complex multi-scale systems

The focus of this activity will be on highly exploratory research using a common methodological framework to quantify the resilience of SES and their components. The goal of this research is not to develop predictive models, but rather to provide a conceptual and theoretical framework that facilitates and stimulates interdisciplinary dialog and sensitises the BASC community to the importance of emergent properties and propagation of uncertainties in complex multi-scale systems.

Two positions were filled to advance this work:

> Post-doctoral researcher « Models coupling » - Marc Stéfanon – 36 months

> Engineer « Streamlining databases for the simulation of systems coupling economy, ecology, biosphere and atmosphere functioning » - Juliette Adrian – 24 months

Results

The objective of the BASC Flagship Project 5 (FP5) was to mobilize the community of scientists within BASC and associated with BASC to develop and apply coupled climate-land systems models (also referred to as "socio-ecological systems" models) at landscape to regional scales that couple climate, air quality, ecosystem functioning, biodiversity, land use and economics. Five activities contributed to achieving, at least partly, these objectives:

1. Organization of workshops bringing modelers together from a wide range of disciplines to create the foundations for building coupled climate-land system models. Several workshops created essential interdisciplinary collaborations and laid out strategies for building coupled climate- land system models. The workshops did not lead to a new coupled climate-land system model being developed within the timeframe of the project, which was the original goal, but they did establish the foundations for a flagship project in the second phase of BASC (STIMUL) that has a concrete framework for developing such model couplings. Workshops also contributed to structuring the scientific community that put together the successful proposal for the "Institut de Convergence CLAND". 

2. Creation of an on-line catalog of models developed and/or used by BASC teams. This web-based catalog — accessible on the Labex BASC web site — consists of short, structured descriptions of models used by BASC teams to simulate various components of the climate-land system interactions.

3. Demonstrations of the importance of coupling models for understanding climate-land system interactions. These studies demonstrated that i) land use can, under certain circumstances, have impacts on regional climate that are on roughly the same magnitude as those due to global climate warming, ii) ecosystem models can provide a powerful means of testing regional climate models, and iii) fully integrated models of land use and climate drivers of species distributions can substantially alter the understanding of the factors underlying presence and absence.

4. Mobilization of databases as the basis for building coupled models. A new model has been developed that couples a model agricultural offer with a simplified version of a mechanistic crop production model at the European scale. This work required the mobilization of a wide range of agricultural, environmental and economics databases supported by FP5. This model provides a means of testing the impacts of agricultural policy and management practices on farming economies and crop production for Europe.

5. Building international collaborations with other teams working on coupled land system models. BASC FP5 helped support the organization of and participation in an on-going international effort to couple global socio-economic development models (in particular the "Shared Socio- economic Pathway" scenarios being developed in support of IPCC) with models of impacts on ecosystem function and biodiversity.

==> Access the powerpoint presentation of the results of the Flagship 5 project (LabEx Days 2017)

Publications (non exhaustive)

> Ay, J. S., J. Guillemot, N. Martin-StPaul, L. Doyen and P. Leanly, 2017. "The economics of land use reveals a selection bias in tree species distribution models." Global Ecology and Biogeography 26(1): 65 77.8

> Lemordant, L., P. Gentine, M. Stefanon, P. Drobinski and S. Fatichi, 2016. "Modification of land atmosphere interactions by CO2 effects: Implications for summer dryness and heat wave amplitude." Geophysical Research Letters 43(19): 10240-10248.

> Stéfanon, M., S. Schindler, P. Drobinski, N. de Noblet-Ducoudre and F. D'Andrea, 2014. "Simulating the effect of anthropogenic vegetation land cover on heatwave temperatures over central France." Climate Research 60(2): 133-146.

> Stéfanon, M., N. K. Martin-StPaul, P. Leadley, S. Bastin, A. Dell’Aquila, P. Drobinski and C. Gallardo, 2015. "Testing climate models using an impact model: what are the advantages?" Climatic Change 131(4): 649-661.

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The non-exhaustive inventory of models available in BASC with synthetic presentations are accessible here.