模拟酸雨对白术根际微生物的影响

用不同pH值的模拟酸雨处理中药植株白术及其种植土壤,测定了白术根际微生物数量的变化.结果表明,酸雨影响白术根际微生物的生长,根际微生物总量随酸雨酸度的加大而减少;酸雨对白术根际环境中的细菌、放线菌、氮素生理群和碳素转化菌都有明显的抑制作用;适当的酸雨刺激（pH为5.0、4.5）促进了真菌的生长,但当酸雨pH＜4.5时,则抑制真菌的生长.植物根系的存在,可使酸雨对根际微生物各个类群的影响不同于非根际土壤微生物.

Influence of simulated acid rain on the rhizospheric microorganisms in Atractylodes macrocephala

The populations of bacteria, actinomycetes, fungi and several microbial functional groups were measured in rhizosphere of Atractylodes macrocephala and their host soil sprayed by simulated acid rain solutions with different pH values. The results showed that microbial population was obviously affected and the microbial biomass was decreased with the decline of simulated acid rain pH. The simulated acid rain could inhibit the numbers of bacteria, actinomyces, physiological groups for nitrogen cycling and cellulose-decomposing. When pH value of simulated acid rain was 4.5 or higher, population of fungi could be stimulated, and when lower than 4.5, it was inhibited. However, with the presence of roots, the effect of simulated acid rain on rbizospbere microbes of Atractylodes macrocephala was different from that on non-rhizosphere microbes.