采煤塌陷复垦区先锋植物根际微生物数量的变化

采用以空间代替时间的方法,研究了采煤塌陷区复垦后土壤自然演替状况下先锋植物根际微生物数量和组成的变化,探讨不同先锋植物根际微生物变化的特征和规律。结果表明,不同先锋植物其根际微生物的数量不同,其中,复垦1年后的土壤,狗尾草Setaria viridis(L.)Beauv.]的根际细菌、真菌和放线菌数量及微生物总量均大于刺儿菜Cirsium setosum Willd.ex MB.]的根际微生物数量,复垦3年后则相反;两种先锋植物根际微生物的数量均随着复垦年限的延长而显著增加,其中,细菌和放线菌数量增加的较快,因此,细菌所占微生物总量的比例随着复垦年限延长而增加,而真菌的比例降低。复垦后土壤上的先锋植物根际效应十分明显,从微生物类群来看,根际效应是真菌放线菌细菌,从植物类别来看,复垦1年后的土壤上,先锋植物狗尾草的根际效应大于刺儿菜,但复垦3年后则相反,说明随着物种和时间的变化,根际效应也发生变化。

Research on Microbial Amount in Rhizosphere of Pioneer Plant in Reclaimed Core-Mining Subsidence Area

The method that spatial sequence instead of time successional sequence was applied to analyze the soil microbial amount and composition in rhizosphere of pioneer plant in reclaimed core-mining subsidence area, to explore the change characteristics and law of rhizosphere microorganism of pioneer plant. The results showed that the rhizosphere microorganism quantity varied in different pioneer plants. The quantity of bacteria, actinomycetes, fungi and total microorganism of Setaria viridis (L.) Beauv. was more than that of Cirsium setosum Willd. ex MB. after 1 year of land reclamation, while the quantity was contrary after 3 years of land reclamation. The number of rhizospheric microorganism of two pioneer plants increased sig-nificantly with the extension of reclamation time. Furthermore, the range of increase in bacteria and actinomycetes was larger than that of fungi. Therefore, the percentage of bacteria increased with time, but fungi decreased. Rhizospheric effect was sig-nificant in reclaimed core-mining subsidence area and rhizospheric effect among the microorganism groups was as followed:fungi > actinomycetes > bacteria. Rhizospheric effect of two pioneer plants was as followed: S. viridis (L.) Beauv. > C. se-tosum Willd. ex MB. after 1 year of land reclamation, while it was contrary after 3 years of land reclamation. The study indi-cates that rhizospheric effect varies with species and time.