Microbial communities in Iceland surprisingly resistant to climate change

Date: 19 December 2017

Introduction: Effects of warming over 50 years were even reduced compared to changes in the first decade.

How stable are ecosystems under climate change? This question gets ever increasing scientific attention. And while they are not as visible as plant and animal communities, soil microbial communities are quintessential to look at in this context. They have a strong influence on the carbon stocks in the soil, and an expected diversity change and potential increased activity due to increased temperature could have drastic effects on the exchange of carbon between soil and atmosphere (and hence on CO2 and CH4 concentrations in the atmosphere, the main greenhouse gases).

That is why Dajana Radujkovic (Global Change Ecology Centre, Research Group Plants and Ecosystems) studied the change in microbial communities in subarctic grasslands in Iceland. High-latitude systems are predicted to be particularly vulnerable to warming. Dajana took advantage of a natural coincidence where soil temperatures have increased due to geothermal activity, much in the same manner as expected due to the climate change.

Dajana: “We thought that long-term exposure (longer than 50 years) would intensify the effect of warming on soil bacterial and fungi compared to shorter-term exposure (less than a decade). The results were however unexpected: long-term exposure did not produce a stronger effect on microbial communities, it even had less of effect than the short-term exposure.”

These finding suggest that the effects of warming on microbial community composition observed in shorter-term experiments, in subarctic grasslands, are not likely to underestimate effects over larger time scales—in contrast, there might be a risk of overestimation. Microbial community composition in high-latitude ecosystems may thus be less sensitive to climate warming than previously expected.

The results were published in FEMS Microbiology Ecology.