SRA

Extreme weather events such as droughts are on the rise in the course of global change. However, little is known about the microbiome responses to natural drought in restored fen peatlands. Different proxies for changes in structure and/or function of microbiomes have been developed, allowing assessing microbiome dynamics at multiple levels. In the summer of 2018, a severe heatwave accompanying drought happened across Europe. We investigated both the prokaryotic and eukaryotic microbiome structures and functions in two rewetted fen peatlands in northern Germany before, during and after the drought happened. Using both amplicon and metatranscriptomic sequencings, we compared four different proxies, i.e. 16/18S rRNA gene, 16/18S rRNA transcript, mRNA taxonomy and mRNA function. Interestingly, both prokaryotic and eukaryotic microbiomes showed significant changes in their structure and function in times of drought using all proxies except for 16S rRNA gene which indicated no significant changes in prokaryotic microbiomes. With mRNA taxonomy, drought was found to explain the variations the most in microbiome compositions, suggesting that this proxy can be promising and robust in revealing the microbial dynamics. To our knowledge, this is the first study comparing all these proxies to reveal the dynamics of both prokaryotic and eukaryotic microbiomes in soils. With this multi-proxy-comparison, this study shows that microbiomes are sensitive to (extreme) weather changes in rewetted fens, and the associated microbial changes might contribute to ecological consequences.