Bridging Human and Natural Sciences for a Better Understanding of Urban Floral Patterns: the Role of Planting Practices in Mediterranean Gardens
Audrey Marco, Laboratoire Population Environnement Développement, Université de Provence
Carole Barthelemy, Laboratoire Population Environnement Développement, Université de Provence
Thierry Dutoit, Institut Méditerranéen d'Ecologie et de Paléoecologie, Université d'Avignon
Valérie Bertaudière-Montes, Laboratoire Population Environnement Développement, Université de Provence
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Biodiversity research in urban settings constitutes an interdisciplinary field combining both the natural and human sciences. A full understanding of the patterns and processes underlying the dynamic of biodiversity in urban ecosystems needs to include humans in models of ecological functioning. We focus on the planting practices of gardeners to identify the bottom-up and top-down human influences on the floral diversity of the Mediterranean gardens in an urbanizing rural zone. An initial ecological study of cultivated flora in 120 private gardens showing floristic pattern variations along an urbanization gradient was combined with a sociological survey. This survey aimed at collecting reasons for planting in gardens in connection with cultivated species. These reasons were classified into categories and analyzed according to the frequency of cultivated species within the entire gradient. Floristic heterogeneity in gardens, represented by the richness of uncommon species, is predominantly caused by social factors, particularly related to the practices and social networks of gardeners who tend to diversify the range of species that are planted. Floristic uniformity, defined by a high frequency of occurrence of plant species, results not only from social factors but also from natural factors that exert high pressure in the Mediterranean region. This “floristic norm” is also influenced by the urban context, which can modify the expression of natural and social factors and lead to differences in plant species compositions between housing density zones. More generally, these results stress the importance of considering both individual choices and city-level influences through an interdisciplinary approach to understanding the underlying processes that establish urban biodiversity patterns at a small scale.
environmental pressures; floristic heterogeneity; floristic norm; social network; urban biodiversity; urbanization gradient