Aridity and geochemical drivers of micronutrient and …
samples were collected from 148 sites located in drylands of six countries (Portugal, Spain, Italy, Hungary, Greece and Malta; Figure S1) (Prăvălie, 2016) in 2009 and 2012, following a standardised sampling protocol as part of the survey LUCAS (see Orgiazzi et al., 2018 for details).