节点文献
踩踏干扰下生物结皮土壤可培养微生物数量
Dynamic of Culturable Microorganisms in Biological Soil Crusts under Trampling Disturbance
【摘要】 生物结皮显著影响土壤微生物数量和群落组成。干扰是自然界常见现象,可引起生物结皮盖度及组分发生改变,进而导致生物结皮土壤微生物群落结构的变化。以发育8年的生物结皮为研究对象,采用平板培养法,研究了干扰下生物结皮层和其下0~2 cm土壤微生物数量的动态变化。结果表明:(1)干扰第2天不同菌种均有响应。生物结皮层土壤细菌、真菌和放线菌数量波动范围分别为91.2×105~303.5×105cfu·g-1,0~487.2×103cfu·g-1和23.0×105~376.1×105cfu·g-1;下层0~2 cm波动范围分别为65.6×105~792. 3×105cfu·g-1,8.0×103~506. 3×103cfu·g-1和17.3×105~801.3×105cfu·g-1。(2)生物结皮层和下层0~2 cm土壤细菌数量分别在干扰后第10天和第7天恢复稳定,真菌数量在第16天和第8天趋于平稳,放线菌数量在第8天和第4天恢复稳定。生物结皮层较0~2 cm土壤微生物数量恢复稳定滞后。(3)重新稳定后生物结皮层和下层0~2 cm细菌数量较干扰前分别下降了81.8%和79.6%.生物结皮层真菌数量显著增加,是干扰前的7.43倍;下层0~2 cm真菌数量下降了70.1%。生物结皮层和下层0~2 cm放线菌数量较干扰前分别降低46.5%和72.6%。(4)干扰显著改变土壤微生物群落结构,受影响程度细菌>放线菌>真菌变为放线菌>细菌>真菌。干扰可显著影响土壤微生物数量,但是随着时间延长微生物数量又会达到一个新的稳态,在研究微生物对干扰响应时,采样时间是研究结果的一个重要影响因素。
【Abstract】 Biological soil crusts( biocrusts) exert remarkable influence on soil microorganism quantity and community structure. Disturbance is a ubiquitous natural phenomenon,which may cause changes in the coverage and composition of biocrusts and consequently affect soil microorganisms. The dynamic variation of microorganism quantity of biocrust layer and 0-2 cm soil layers in an eight-year development biocrustal soil were investigated by using plating method in order to reveal the effect of disturbance on soil microorganisms. The results showed that:( 1) The quantity of bacteria,fungi and actinomyces changed on the second day since disturbance. Moreover,the fluctuation amplitude of quantity of bacteria,fungi and actinomyces in the biocrust layer were 91.2×105-303.5×105 cfu·g-1,0-487.2×103 cfu·g-1,and 23.0×105-376.1×105 cfu·g-1,respectively. The fluctuation amplitude of quantity of bacteria,fungi and actinomyces in 0-2 cm soil layer were 65.6×105-792.3×105 cfu·g-1,8.0×103-506.3×103 cfu·g-1 and 17.3×105-801.3×105 cfu·g-1,respectively.( 2) Bacterial quantity in biocrust layer and 0-2 cm soil layers restabilized in the tenth and seventh day after disturbance,respectively. Quantity of fungal in biocrust layer and 0-2 cm layers tended to be stable after 16 and 8 days of disturbance,respectively. Quantity of soil actinomyces in biocrust layer and 0-2 cm soil layers reached a new stabilization in eight and four days since disturbance,respectively.The stable period of soil microbial quantity lagged behind in biocrust layer than 0-2 cm soil layer.( 3) Bacterial quantity decreased by 81.8% and 79.6% in biocrust layer and 0-2 cm soil layers in the new stable stage compared to that before disturbance. However,fungal quantity was 7.43 times higher in biocrust layer,and it decreased by 70.1% in 0-2 cm soil layer. Further,quantity of actinomyces decreased by 46.5% and 72.6% in biocrust layer and 0-2 cm soil layers,respectively.( 4) Disturbance had a significant effect on soil microbial community structure,the proportion of different soil microorganisms became actinomyces>bacteria>fungi from bacteria>actinomyces>fungi.Results of the study suggested that disturbance can significantly affect soil microbial quantity,but the quantity of microorganisms will reach a new stable status as time goes on. Therefore,the sampling time could be an important influence factor in the study of disturbance on soil microorganisms.
【Key words】 biocrusts; bacteria; fungi; actinomyces; dynamic response;
- 【文献出处】 中国沙漠 ,Journal of Desert Research , 编辑部邮箱 ,2019年01期
- 【分类号】S154.3
- 【网络出版时间】2018-10-25 10:06
- 【被引频次】2
- 【下载频次】299