Soil compartment is a major determinant of the impact of simulated rainfall on desert microbiota
Soil compartment is a major determinant of the impact of simulated rainfall on desert microbiota
复制标题
DOI：
10.1111/1462-2920.13474
复制
发表时间：
2016-12-01
影响因子：
5.1
通讯作者：
McGenity, Terry J.
中科院分区：
文献类型：
--
作者：
Aslam, Shazia N.;Dumbrell, Alex J.;McGenity, Terry J.
虽然沙漠土壤支持功能重要的微生物群落，影响植物生长和影响许多生物地球化学过程，未来降水模式的变化对微生物群及其活动的影响在很大程度上是未知的。我们进行了原位实验，以调查模拟降雨对细菌群落的影响与广泛的多年生灌木，Rhazya stricta在阿拉伯沙漠土壤。细菌群落组成是不同的三个不同的土壤隔间：表面生物结皮，根附着，和更广泛的根际。模拟降雨没有显着影响的整体细菌群落组成，但观察到一些人口水平的反应，特别是在土壤结皮Betaproteobacteria，鞘氨醇杆菌，芽孢杆菌变得更加丰富。细菌生物量在营养丰富的地壳增加了三倍，一个星期后浇水，而根际没有变化，尽管其更高的保水性。这些发现表明，在降雨事件之间，沙漠土壤微生物群落进入停滞状态，物种更替有限，当有水可用时，微生物群落迅速且相对均匀地重新活跃。然而，在地壳中的微生物，这是相对丰富的营养物质和有机质，主要是水分限制，相比之下，根际微生物的营养和水分的共同限制。
Although desert soils support functionally important microbial communities that affect plant growth and influence many biogeochemical processes, the impact of future changes in precipitation patterns on the microbiota and their activities is largely unknown. We performed in-situ experiments to investigate the effect of simulated rainfall on bacterial communities associated with the widespread perennial shrub, Rhazya stricta in Arabian desert soils. The bacterial community composition was distinct between three different soil compartments: surface biological crust, root-attached, and the broader rhizosphere. Simulated rainfall had no significant effect on the overall bacterial community composition, but some population-level responses were observed, especially in soil crusts where Betaproteobacteria, Sphingobacteria, and Bacilli became more abundant. Bacterial biomass in the nutrient-rich crust increased three-fold one week after watering, whereas it did not change in the rhizosphere, despite its much higher water retention. These findings indicate that between rainfall events, desert-soil microbial communities enter into stasis, with limited species turnover, and reactivate rapidly and relatively uniformly when water becomes available. However, microbiota in the crust, which was relatively enriched in nutrients and organic matter, were primarily water-limited, compared with the rhizosphere microbiota that were co-limited by nutrients and water.