The river corridor: networks already in place needing strengthening and protecting - Descriptions dedicated to ecological questions with a cognitive and operational scope

Abstract

The approach presented here consists in building a series of spatial indicators for the river corridor watercourse and riparian corridors) on the entire network of metropolitan France and then comparing them to functional ecological responses (e.g. biodiversity, trophy and resilience). In order to reflect the state and connectivity of habitat mosaics embedded within the corridor, these indicators measure the appropriate composition and/or configuration present within the landscape at the local and network scales. Building homogeneous indicators over the entire French hydrographic network has allowed us to investigate specific and quantitative relationships not only with regard to physicochemical responses (e.g. water quality), but also in relation to the potential spatial distribution of mammals (e.g. otters and beavers). We describe here an analysis concerning otters in the Loire watershed. The presence of wooded riparian corridors combined with a lack of alteration of the physical environment of the watercourses offer favorable conditions for colonization by this species. Such configurations were mapped while taking into account the density of the hydrographic network. Results identify structural and functional networks which meet the ecological needs of the species at different scales. They provide effective support to guide management strategies aimed at strengthening and protecting such areas.