Abstract
Urbanization modifies environments worldwide creating opportunities for the establishment of invasive species, natives or non-natives, a main driver of global change. To understand the process of biological invasion, we need to decipher the interactions between urbanization and species traits. Within the Mediterranean Tapinoma nigerrimum species complex (Hymenoptera, Formicidae), Tapinoma darioi Seifert & al., 2017 and Tapinoma magnum Mayr, 1861 have spread in continental European cities and exhibit “tramp”-species traits. In contrast, T. nigerrimum (Nylander, 1856) is not expanding its range and does not exhibit characteristics of tramp ant species. We investigated whether the distribution of these species differed in relation to land use. We chose Montpellier (Mediterranean France) as a study site because it combines the presence of all three species with rapid urbanization. Occurrence data were generated by systematically sampling all Tapinoma colonies over 926 sites, > 500 m away from one another, over a 60 × 25 km area. Species were identified using 15 microsatellite markers. Four land-cover classes (urbanization, agricultural, natural, water) were used for landscape analyses based on 250 m-radius buffer zones. Tapinoma nigerrimum was found at 197 sites (21.27% of occurrences), T. darioi at 78 sites (8.42%), and T. magnum at 6 sites (0.65%). The probability of occurrence of T. darioi was positively correlated with urbanization up to a threshold of 75% impervious land-cover, negatively correlated with natural land-cover, and was higher near the coast. In contrast, T. nigerrimum occurred less often at sites with impervious land-cover and near the coast, and more frequently in natural areas. These distinct distributions support an association between urbanization and species exhibiting tramp traits, and highlight the importance of adapting land management to control biological invasions