Št'ovíček Adam, Azatyan Ani, Soares M Ines M, Gillor Osnat
Zuckerberg Institute for Water Research, Blaustein Institutes for Desert Research, Ben-Gurion University of the NegevMidreshet Ben Gurion, Beersheba, Israel.
Front Microbiol. 2017 Jun 14;8:1078. doi: 10.3389/fmicb.2017.01078. eCollection 2017.
Hot desert ecosystems experience rare and unpredictable rainfall events that resuscitate the arid flora and fauna. However, the effect of this sudden abundance of water on soil microbial communities is still under debate. We modeled varying rainfall amounts and temperatures in desert soil mesocosms and monitored the microbial community response over a period of 21 days. We studied two different wetting events, simulating heavy (50 mm) and light (10 mm) rain, as well as three different temperature regimes: constant 25° or 36°C, or a temperature diurnal cycle alternating between 36 and 10 °C. Amplicon sequencing of the bacterial ribosomal RNA revealed that rain intensity affects the soil bacterial community, but the effects are mitigated by temperature. The combination of water-pulse intensity with lower temperature had the greatest effect on the bacterial community. These experiments demonstrated that the soil microbial response to rain events is dependent not only on the intensity of the water pulse but also on the ambient temperature, thus emphasizing the complexity of bacterial responses to highly unpredictable environments.
炎热的沙漠生态系统降雨稀少且难以预测，而这些降雨会使干旱的动植物复苏。然而，这种突然大量的水分对土壤微生物群落的影响仍存在争议。我们在沙漠土壤中型生态系统中模拟了不同的降雨量和温度，并在21天的时间里监测了微生物群落的反应。我们研究了两种不同的湿润事件，模拟了大雨（50毫米）和小雨（10毫米），以及三种不同的温度条件：恒定的25°C或36°C，或在36°C和10°C之间交替的昼夜温度循环。对细菌核糖体RNA的扩增子测序显示，降雨强度会影响土壤细菌群落，但这种影响会因温度而减弱。水脉冲强度与较低温度的组合对细菌群落的影响最大。这些实验表明，土壤微生物对降雨事件的反应不仅取决于水脉冲的强度，还取决于环境温度，从而强调了细菌对高度不可预测环境反应的复杂性。
