不同放牧强度下陇东天然草地土壤微生物三大类群的动态特征

对陇东黄土高原天然草地的4个放牧处理(0、2.7、5.3和8.7只羊/hm2)生境下的土壤微生物三大类群时空动态特征进行了研究。结果表明,同一放牧强度下不同土层(0～10、10～20、20～30 cm),随着土层深度的增加土壤微生物三大类群呈减少趋势;在不同放牧强度下同一土层土壤微生物三大类群的数量不同,未放牧、轻度放牧条件下微生物种群数量较高,而过度放牧的天然草地土壤微生物数量最高;不同放牧条件下,土壤微生物三大类群表现出基本一致的变化趋势,真菌、细菌最高值出现在9月,放线菌最高峰出现在11月。

Changeable characteristics of three soil microbial groups under different grazing intensities in Loess Plateau

An experiment was conducted to investigate the Changeable characteristics of three soil microbial groups at four grazing intensities (0,2.7,5.3 and 8.7 sheep/hm2) in Loess Plateau. The results of this study indicated that the quantities of microbial gradually reduced from 010 cm layer, 020 cm layer, to 2030 cm layer at each grazing intensities. Total number of microorganism was different under different grazing intensities in the same depth layer, indicating that the number was higher at no grazing and moderate grazing intensity, and the number was the highest at overgrazing in Loess Plateau. The quantities of microbial group was not different among grazing intensities, indicating that the highest number of fungi and bacteria were founded in September and the highest number of actinomycete were founded in November.