Institute of Microbiology, Center for Functional Genomics of Microbes, University of Greifswald, Felix-Hausdorff-Str. 8, 17487, Greifswald, Mecklenburg-Vorpommern, Germany.
Geobotanik, Ruhr-Universität Bochum, Bochum, Germany.
Microb Ecol. 2021 Aug;82(2):403-415. doi: 10.1007/s00248-020-01667-7. Epub 2021 Jan 16.
Winter temperatures are projected to increase in Central Europe. Subsequently, snow cover will decrease, leading to increased soil temperature variability, with potentially different consequences for soil frost depending on e.g. altitude. Here, we experimentally evaluated the effects of increased winter soil temperature variability on the root associated mycobiome of two plant species (Calluna vulgaris and Holcus lanatus) at two sites in Germany; a colder and wetter upland site with high snow accumulation and a warmer and drier lowland site, with low snow accumulation. Mesocosm monocultures were set-up in spring 2010 at both sites (with soil and plants originating from the lowland site). In the following winter, an experimental warming pulse treatment was initiated by overhead infrared heaters and warming wires at the soil surface for half of the mesocosms at both sites. At the lowland site, the warming treatment resulted in a reduced number of days with soil frost as well as increased the average daily temperature amplitude. Contrary, the treatment caused no changes in these parameters at the upland site, which was in general a much more frost affected site. Soil and plant roots were sampled before and after the following growing season (spring and autumn 2011). High-throughput sequencing was used for profiling of the root-associated fungal (ITS marker) community (mycobiome). Site was found to have a profound effect on the composition of the mycobiome, which at the upland site was dominated by fast growing saprotrophs (Mortierellomycota), and at the lowland site by plant species-specific symbionts (e.g. Rhizoscyphus ericae and Microdochium bolleyi for C. vulgaris and H. lanatus respectively). The transplantation to the colder upland site and the temperature treatment at the warmer lowland site had comparable consequences for the mycobiome, implying that winter climate change resulting in higher temperature variability has large consequences for mycobiome structures regardless of absolute temperature of a given site.
预计中欧地区的冬季气温将会升高。随之而来的是，积雪覆盖量将会减少，导致土壤温度的变异性增加，而土壤结霜的潜在后果则取决于例如海拔高度等因素。在这里，我们在德国的两个地点（一个积雪较多的较冷和潮湿的高地地点，以及一个积雪较少的较温暖和干燥的低地地点）进行了实验，评估了冬季土壤温度变异性增加对两种植物（普通羊茅和黑麦草）根相关真菌群落的影响；在这两个地点的春季 2010 年设置了中尺度单种培养物（土壤和植物均来自低地地点）。在下一个冬季，通过在两个地点的土壤表面使用架空红外加热器和加热线启动了一个实验性增温脉冲处理。在低地地点，增温处理导致土壤结霜的天数减少，平均日温度振幅增加。相反，该处理在高地地点没有导致这些参数发生变化，而高地地点通常是受结霜影响更大的地点。在随后的生长季节（2011 年春季和秋季）之前和之后对土壤和植物根进行了采样。使用高通量测序对根相关真菌（ITS 标记）群落（真菌组）进行了分析。结果发现，地点对真菌组的组成有深远的影响，在高地地点，真菌组主要由快速生长的腐生物（Mortierellomycota）组成，而在低地地点，则由植物种特异性共生体（例如，普通羊茅的 Rhizoscyphus ericae 和 Microdochium bolleyi，以及黑麦草的）组成。将植物移植到较冷的高地地点和在较温暖的低地地点进行温度处理对真菌组产生了类似的影响，这表明冬季气候变化导致温度变异性增加，无论特定地点的绝对温度如何，都会对真菌组结构产生重大影响。
