The biomass of P.flaccidum community in June and July was studied. The result showed that the aboveground biomass in June and July was 90.97 g/m 2 and 95.02 g/m 2 respectively; the underground biomass was 324.00 g/m 2 and 452.61 g/m 2 respectively.

• 研究了黄土区白草群落6月和7月的生物量，测定结果：6月和7月地上生物量分别为90.；97g/m2和95