“…Both Glomeromycotina and Mucoromycotina fungi (and dual fungal symbioses involving both fungal partners) gain a greater proportion of recently fixed photosynthates when grown under an elevated atmospheric [CO 2 ] compared to current ambient conditions (Drigo et al, 2010;Field et al, 2012Field et al, , 2015bField et al, , 2016a, decreasing further in response to subambient atmospheric [CO 2 ] (Zhang et al, 2015). Nutrient transfer from fungus to plant appears to respond differently to changing [CO 2 ] according to both fungal and plant host identity (Field et al, 2012(Field et al, , 2015b(Field et al, , 2016aWerner et al, 2018). For instance, Glomeromycotina-associated nonvascular plants exposed to elevated atmospheric [CO 2 ] assimilate more fungal-acquired 33 P tracer than under ambient atmospheric [CO 2 ] (Field et al, 2012;Werner et al, 2018).…”