1. Institute of Bioscience and BioResources (IBBR), Italian National Council of Research, Bari, Italy
2. Department of Planning, Design and Technology of Architecture, Section Environment and Landscape, Sapienza University of Roma, Rome, Italy
3. Centre Alpien de Phytogéographie, Fondation J.-M. Aubert, Champex-Lac
4. Section of Biology, University of Geneva, Chambésy, Switzerland