Potential contributions of green spaces at business sites to the ecological network in an urban agglomeration: The case of the Ile-de-France region, France

For several decades, the sprawling of urbanisation has resulted in the loss of natural habitats and in landscape fragmentation and thus represents one of the main causes of the erosion of biodiversity. Green spaces in urban areas help maintain ecological connectivity and provide ecosystem services to citizens. The impact of urban green spaces on the conservation of biodiversity and their contribution to ecological networks in urban areas have been studied. However, little is known about the area occupied by green spaces at business sites (GSBS) or about their organisation within the urban matrix and their possible contribution to the maintenance of functional connectivity at local and regional scales. This study analysed the evolution in the dynamics and locations of business sites over the past 30 years in the Ile-de-France region. Cartographic data allowed us to identify GSBS which spanned 8700 ha and represented 8% of the urban green spaces forming the herbaceous network. Using a graph theoretic modelling approach, we quantified the potential contribution of GSBS to regional connectivity. We demonstrated that GSBS did not add to connectivity in terms of total area but rather through the density of the links that these sites shared with other green spaces or via their strategic position in the network, i.e., their capacity to serve as stepping stones. The contribution of GSBS was greatest in suburban and pericentral sectors, where most business activities have been developed in the past 30 years and land resources remain available for green space development. (C) 2014 Elsevier B.V. All rights reserved.