Scientists in Germany studying how microorganisms living in soil react to the effects of climate change have warned that essential bacteria and other organisms could be jolted out of step, hampering their ability to maintain healthy soils.

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The researchers, from two institutes based in Munich, warned on Wednesday that extreme weather events like long periods of drought and heavy rainfall have a strong impact on the metabolic activity of microbes (their digestion processes that nourish soils). These changes may lead to a change in the nutrient balance of soils and, in extreme cases, may even increase greenhouse gas emissions like nitrous oxide from soils.

As healthy soils – which are said to contain up to a quarter of all life on the planet – take hundreds of years to build up, soil scientists treat soil as a non-renewable resource. In October, two of the UK's research councils announced funding to support the training and development of more soil scientists to help preserve this most vital resource.

Even so, mainstream research and industry institutions are only just becoming aware of the importance of soils to agro-ecosystems and the wider environment. At a Soil Symposium late last month in Solihull, delegates heard that the UK faces a soil crisis, but that through better management and protection healthy soils can be  safeguarded.

Sharing their findings this week, the German scientists said that in order to observe the impact of climate change on soil microorganisms under as natural conditions as possible, they moved young beech seedlings from a wetter, cooler area to a warmer site that would mimic the temperature and precipitation levels envisaged by certain climate models.

"We tried to keep initial soil type and nutrient contents in soil as comparable as possible to avoid additional factors influencing our data," said Prof. Dr. Michael Schloter, who worked on the study. "In addition to these natural changes due to the transplantation of the trees, we exacerbated the scenario by simulating long periods of drought followed by heavy rainfall."

The researchers discovered that transferring seeds to a warmer, drier setting led to a drastic change in the metabolic activity of microorganisms within the soil on its own. When they simulated extreme weather events, the effects were even more pronounced.

Dr. Silvia Gschwendtner, who also carried out the research, said bacteria involved in denitrification (taking nitrates from soils and creating nitrogen oxide gasses) were stimulated and increased their activity as a result of the change.

"This has an impact on the competition between plants and microorganisms for nitrogen." Dr. Gschwendtner said. "[It] may also lead to increased emission rates of greenhouse gas N₂O."