1 Plant Ecology, Institut für Biologie, Freie Universität Berlin, D-14195, Berlin, Germany.
2 Laboratory of Ecology and Environmental Protection, Faculty of Agriculture, Aristotle University of Thessaloniki, 541 24, Thessaloniki, Greece.
3 State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100091, China.
4 University of Chinese Academy of Sciences, PO Box 2871, Beijing, China.
5 Department of Biology, University of York, York, YO10 5DD, UK.
6 Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), D-14195,, Berlin, Germany.
7 Department of Soil and Water Conservation, CSIC-Centro de Edafología y Biología Aplicada del Segura, PO Box 164, Campus de Espinardo, 30100, Murcia, Spain.
8 School of Earth and Environmental Sciences, The University of Manchester, Manchester, M13 9PT, UK.