Inter- and intra-site variation of microarthropod communities in urban parks

Urban parks are one of the most represented green spaces in cities and can support biodiversity. However, most of the studies demonstrating the role of urban biodiversity do not take into account soil biodiversity, which represents at least 1/4 of the world's taxonomic diversity. Among these soil organisms, microarthropods are recognised bioindicators because of their role in soil functioning but also because of their high abundance and sensitivity to a variety of environmental and anthropogenic factors. With high heterogeneity due to soil, management or localisation, nothing looks less like a park than another park. In this study, our aim is rather to understand how soil biodiversity is affected by the spatial configuration of the parks. To do this, we studied interand intra-park variation in microarthropod communities using taxonomic and functional approaches based on traits. Our results show communities dominated by Acari, with high abundances of Collembola but low specific richness. Inter-park variations were recorded for the species richness and functional composition of Collembola, Oribatidae abundance, texture and metal levels. That may be linked to the age of the sites in relation with soil physicochemical parameters. Intra-park variations were also observed, particularly for biodiversity indices, which could be explained by the fragmentation of the site and patch size. Despite their small size, soil organisms should be considered in park studies and design (configuration and connectivity). Indeed, understanding the distribution patterns of these organisms is important for improving the role of parks within a functional green and brown urban network.