Gardens as an opportunity for biodiversity conservation in peri-urban landscapes – GARLAND

Private gardens make up the largest proportion of urban green spaces and are also the most frequently used type of outdoor space. As such, they contribute significantly to the preservation of urban biodiversity, ecosystem functioning and services, and have been shown to be valuable for human well-being and health, and for promoting everyday experiences of nature for urban dwellers. The GARLAND project focuses on peri-urban gardens, including vegetable gardens, which have been little studied. The suitability of peri-urban gardens for biodiversity is determined by a combination of socio-ecological and environmental factors operating at different scales. The project proposes an interdisciplinary approach with ecology, sociology and geography to explore the social and ecological drivers, motivations and barriers for better biodiversity management in private gardens at both individual and community scales. The main aim of the project is to develop a comprehensive qualitative and quantitative understanding of the determinants of biodiversity within these peri-urban garden socio-ecosystems, in order to identify opportunities for biodiversity conservation. The project will also investigate whether some garden-related practices tend to increase householders' sense of connection with nature, which would be a potential lever for increasing general pro-environmental behaviour among urban dwellers.
The project focuses on two sub-sectors of the extended peri-urban belt of Greater Paris (Île-de-France) with contrasting socio-economic characteristics. The data acquisition process is structured into three work packages. The first one will explore the role played by local public policies on the presence and profile of gardens in the peri-urban and rural areas of the Ile-de-France region. The hypothesis is that local choices made by planning authorities at the city level may conduct to heterogeneous situations in terms of regulations that may foster, or by contrast, hinder garden preservation. The second work package will study the relationship between householders and their gardens while taking into account the socioeconomic context. In particular, the objective is to determine the main householder factors influencing the proportion of vegetated surface in gardens and the heterogeneity of habitats, two parameters that are very determinant for biodiversity. The potential links between householders’ relationships with their garden and the biodiversity within these gardens will also be examined. The third work package will study how the diversity of flowering plants and pollinators within peri-urban gardens are influenced by the interplay between ecological factors (garden and landscape characteristics) and social factors (householder and urban characteristics). Flowering plants and pollinators were chosen as study models for the biodiversity analyses, because they are prevalent in many gardens and comparatively easy to inventory, and respond to landscape structure at a relatively small spatial scale. At the societal level, the project should allow to identify potential levers for action and to co-construct solutions with stakeholders to promote garden biodiversity at both the municipal and householder level.