3.2 Plant above- and belowground biomass
Eight, seven and three dominant species were sampled respectively in the desert steppe, dry typical steppe and wet typical steppe communities to determine their phytolith and PhytOC contents; these species contributed to 87.58%, 93.65% and 94.39% of the aboveground biomass of the three plant communities (Table 2). The measured aboveground community biomass were 562.27±49.28, 1471.99±110.82 and 1120.09±52.98 kg ha-1, and the estimated belowground biomass (0-70cm) were 4227.99±456.20, 8639.89±543.77 and 8643.74±491.55 kg ha-1 in the desert steppe, dry typical steppe and wet typical steppe, respectively. The biomass of major plant species in these communities were shown in Table 3.