3.4 Community-weighted mean contents of phytolith and PhytOC
The community-weight mean phytolith content (phytolithCWM) and PhytOC content (PhytOCCWM) in the above- and belowground plant biomass were calculated. As plant belowground biomass was measured at species, not community level, the relative belowground biomass of each species was estimated using the measured relative aboveground biomass (AGB%) and the shoot/root ratio (A/B) of each species, and used to calculate the community weighted mean phytolith content of belowground biomass.
The phytolithCWM was 16.68, 17.94 and 15.85 g kg-1 respectively in the aboveground biomass of desert steppe, dry typical steppe and wet typical steppe, no significant difference being detected among the three steppe types (P >0.05); the PhytOCCWM in the belowground biomass was neither significantly different among the three steppe types (P >0.05), being 86.44, 58.73 and 76.94 g kg-1 for the desert steppe, dry typical steppe and wet typical steppe, respectively (Fig.3). The PhytOCCWMwas 0.68 g kg-1 in the aboveground biomass of desert steppe, which was higher than in that of dry typical steppe (0.48 g kg-1) or wet typical steppe (0.59 g kg-1). The PhytOCCWM in the belowground biomass was 1.11, 0.72 and 1.02 g kg-1respectively in desert steppe, dry typical steppe and wet typical steppe, with no significant difference among these steppes (P >0.05) (Fig.3).