The ESNET project aims to analyse future land use trajectoires and their effects on biodiversity and ecosystem services for the Grenoble urban area.
A multi-source and multi-temporal analysis at fine resolution (15 m) showed that for a total area of 4450 km², 311 municipalities and 769 573 inhabitants, this territory comprising the Grenoble SCoT (273 municipalities) is made of 10% artificial areas, 34% agricultural land, 48% forests, 7% natural and et semi-natural areas and 1% aquatic areas. The dynamics from 1998 to 2009 shows a 6.6% (29 km²) increase in artificial areas, at the expense of agricultural land, and with a strong contrast between predominantly urban or periurban municipalities at lower altitude, primarily concerned by either dense or sprawling urban growth, and rural municipalities which are mainly stable or subject to forest colonisation. This dynamics motivated the Grenoble SCoT territorial plan, and underpins critical issues for biodiversity and ecosystem services. As a project co-constructed with the multiple stakeholders involved in the management of the territory and its resources, ESNET builds on their field knowledge, starting with the identification of main issues linking the demand for ecosystem services and management and planning actions. These issues are structured by the need to reconcile ecological functioning and the uses and sharing of land and resources. The inherent complexity and the multifunctionality of the territory mean that governance must be at the core of the thinking for concerted management across actors at the territorial scale.
Four scenarios consistent with the SCoT plan and with the Montagne 2040 scenarios proposed by the Rhône-Alpes Region were built using a participative approach with the project’s stakeholders and actors from the different socio-economic sectors. These scenarios are translated in terms of changes in the different types of land use and in agricultural and forest management to support the spatially-explicit modelling of land cover changes. We have selected the DINAMICA modelling platform, using an initial parameterisation based on the analysis of spatial dynamics from 1998 to 2009. Given its high flexibility for parameterization and application, this model is suitable to represent the recent land use change dynamics and major future trajectories under different scenarios, such as urban consolidation or the continuation of periurban sprawl.Such land use and management projections will feed into the modelling of changes for 11 ecosystem services: 3 provisioning services, 2 cultural services and 6 abiotic and biotic regulation services, as well as for terrestrial vertebrate and plant diversity. The originality of ESNET lies in considering ecosystem services not individually, but rather to analyse their joint dynamics using a network approach that identifies functional linkages between services depending on their ecological mechanisms and their responses to climate of management drivers. This approach highlight the fact that any action targeting a given ecosystem service has side effects on other ecosystem services, and makes it possible for stakeholders to understand why. The knowledge of ecosystem services networks will support the identification, a priori or on the basis of scenario projections, of the favourable or negative side effects of management or planning actions targeting a given ecoystem, specific biodiversity of landscape components, or particular ecosystem processes.