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New article on drought and temperature effects on soil microbial C and N cycling in grasslands

Read our new paper on effects of drought and warming on microbial carbon substrate use efficiency and nitrogen use efficiency in two mountain grassland soils.

Mountain regions will experience more intense drought periods and heatwaves in the near future, we have to urgently better understand how these ecosystems respond to such predicted future climate scenarios.The long term drought experiment, conducted since 2008 by the research group of Prof. Michael Bahn from the Institute of Ecology from the University of Innsburck, provides an excellent platform to get a view of the future and study effects of climate change on soil microbes. From selected plots of this drought experiment we collected soil samples (with a group of amazing researchers from the TER-lab at University of Vienna) to conduct short term incubations to 'simulate' a strong heat wave temperature pulse in drought and non-drought treated soils and measured the response of microbial carbon and nitrogen cycling rates.


We found that the microbes in managed grassland incorporated carbon more efficiently than in the abandoned meadow, while the efficiency with which microbes used organic nitrogen are relatively comparable. Under dry conditions microbes reduced carbon metabilism, but the CUE (the carbon use efficiency) remained constant. On the other hand, in dry soils we observed increased N mineralization, but the general response how efficient microbes incorporated N depended on the studied grassland.

Drought seems to stronger affect N cycling, while microbes respond with increased respration to increased temperatures.

At higher temperatures both C and N mineralization was increased, which reduced the efficiency how microbes used their substrateds, but only small interactive effects of drought and temperatures were observed.


For more information check out our paper:

Fuchslueger et al. 2019, in Soil Biology and Biochemistry,

https://doi.org/10.1016/j.soilbio.2019.05.002



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