This document is the accepted manuscript version of the following article: Fournier, B., Frey, D., & Moretti, M. (2019). The origin of urban communities: from the regional species pool to community assemblages in city. Journal of Biogeography. https://doi.org/10.1111/jbi.13772 1 Title: The origin of urban communities: from the regional species pool to 2 community assemblages in city 3 4 Running title: The assembly of urban communities 5 6 Authors: 7 *Fournier, Bertrand; Concordia University; Department of Biology; Montreal, Canada 8 (
[email protected]; +33 79 917 08 41) 9 Frey, David; Swiss Federal Research Institute WSL, Biodiversity and Conservation Biology; 10 Department of Environmental Systems Science, ETH Zurich (
[email protected]) 11 Moretti, Marco; Swiss Federal Research Institute WSL, Biodiversity and Conservation 12 Biology (
[email protected]) 13 14 *Corresponding author 15 16 Abstract: 17 Aim: Cities worldwide are characterized by unique human stressors that filter species based 18 on their traits, potentially leading to biodiversity loss. The knowledge of which species are 19 filtered and at which scale is important to gain a more mechanistic understanding of urban 20 community assembly and to develop strategies to manage human impact on urban 21 ecosystems. We investigate the ecological mechanisms shaping urban community assembly, 22 taking into account changes across scales, taxa, and urban green space types. 23 Location: City of Zurich, Switzerland 24 Taxon: Carabid beetles and wild bees 1 25 Methods: We use a large species occurrence and trait dataset with a high spatial resolution to 26 assess the filtering effect of a medium-sized city on a regional pool of potential colonists.