Résumé
Some organisms are able to disperse by air through passive or active flying and can colonize highly isolated habitat. We can hypothesis than aerial dispersions could be a process of biodiversity development even in isolated town habitats such as some building roofs.
The urban aerial plankton has been poorly studied and we analyzed here the arthropods and seeds trapping small species limited to 0.5-5mm sizes and to a low part of the atmosphere (traps on roofs below 50 meters) in Paris, a center of a very large agglomeration. Using plates of wire meshes with fat, we observed that insects are dominant (Diptera and Hemiptera) when spiders and seeds appeared underrepresented.
At high heights of buildings (and not at low heights), the Landscape Greening Index seems to have a strong positive effect on abundances for spiders, insects and seeds stressing the role of sources and the effect of building barriers on aerial dispersion. These preliminary data encourage research on this process. (C) 2017 Elsevier GmbH. All rights reserved.