土壤细菌和真菌群落的物种续存模式对扰动的响应

Species persistence patterns of soil bacteria and fungi after dilution disturbance

通过研究物种存活概率和局域多度间的关系,对微生物群落动态是否符合中性假说进行检验.使用野外采集的土壤进行土壤微宇宙实验,微宇宙经受了稀释扰动,剔除一些非常稀有的物种.微宇宙经过恢复培养后,用454高通量焦磷酸测序方法分别对土壤细菌16SrRNA基因和真菌18SrRNA基因进行测序,检测多度≥1的物种,从而探究细菌和真菌物种组成相对于源土壤发生的变化.结果发现:恢复生长过程中细菌和真菌物种丰富度都显著降低(>50%);受到扰动的微宇宙恢复生长以后,土壤细菌和真菌物种存活概率与其在源土壤中的初始相对多度之间呈正相关,这个结果符合中性假说的预测,即最初多度较高的物种平均灭绝概率较低.

Relationship of species persistence probability and local abundance was investigated to test whether dynamics of microbial community follows neutral hypothesis. Native soil was collected from the field, and soil microcosms were exposed to dilution disturbances to remove certain very rare species. Bacteria and fungi species compositions in the microcosms after incubation recovery were then compared with source soils, as assessed by 454 high-throughput pyrosequencing of bacterial 16S rRNA genes and fungi 18S rRNA genes, detecting species with an abundance of ≥1 in each community. Species diversity was found to decrease dramatically （by 〉50%）; chances of persistence of soil bacteria and fungi species were positively correlated with initial abundance. These data are consistent with predictions by neutral hypothesis, i. e. , a positive abundance-persistence relationship.