“…Ecologist Heinz Ellenberg was one of the first to develop a quantitative indicator system for vascular plants, and in 1974, he published lists of indicator values (Ellenberg, ) for most species occurring in Central Europe. Ellenberg indicator values (EIV) have been used widely by plant ecologists, mainly in Central Europe (Diekmann, ) and also in other regions, such as Britain (Hill, Mountford, Roy, & Bunce, ) and Northern Europe (Hannus & Von Numers, ; Hedwall & Brunet, ; Hedwall, Nordin, Brunet, & Bergh, ; Hedwall et al., ; Robbins & Matthews, ; Strengbom & Nordin, ) as well as, exceptionally, along large geographic gradients (Verheyen et al., ). EIV have been criticized for being subjective estimates based on expert opinions, that is, not being systematically derived from measurements (Økland, ), and for implying circular reasoning when used as variables substituting real measurements in explaining, for example, plant species composition (plant species in that way only explain their own occurrence).…”