“…Frontiers in Environmental Science | www.frontiersin.org(e.g., Kovda et al, 1990;Lavelle et al, 1995;Lavelle, 1996Lavelle, , 2000Karl, 1997;Schouten et al, 1997;Rampazzo et al, 1998;Yaalon and Arnold, 2000;Barancikova and Madaras, 2003;Calvet, 2003;Blume et al, 2010Blume et al, , 2016Buchan, 2010;Bujnovsky and Vilcek, 2012;Glenk et al, 2012;Madena et al, 2012;Morel et al, 2014;O'Sullivan et al, 2015). In particular, soil functions have become a cornerstone in the long-standing debate on the somewhat vague concepts of "soil quality" and "soil health, " various authors arguing for the existence of absolute values of the notions for any given soil, whereas a growing number of researchers consider that their evaluation makes sense only in relation to specific soil functions (e.g., Sojka and Upchurch, 1999;Bouma, 2002Bouma, , 2010Bouma, , 2014Nortcliff, 2002;Letey et al, 2003;Robert, 2005;Kibblewhite et al, 2008;Keller et al, 2012;Thomsen et al, 2012;Volchko et al, 2014).…”