Climate Change Could Heighten Active Soil Bacteria Diversity, Study Reveals

A new study reveals that active microbes have greater diversity when soils are warmer.

Heightened Active Soil Bacteria Diversity Due to Global Warming

The study "Soil warming increases the number of growing bacterial taxa but not their growth rates" is vital in understanding how soil microbial activity affects the carbon cycle worldwide and climate's possible feedback mechanisms.

Until now, specialists have thought higher soil temperatures could boost microbial growth and increase atmospheric carbon release. However, it has been found that the heightened carbon release is actually due to the activation of previously dormant bacteria.

Andreas Richter, the study's lead author and a professor from the Center of Microbiology and Environmental Systems Science, notes that soil is the largest organic carbon reservoir on the planet. In silence, microorganisms handle the global carbon cycle, break down organic matter, and fuel the release of CO2.

As temperatures go up, communities of microbes are believed to release even more carbon dioxide. This further escalates climate change in a process called soil carbon-climate feedback.

Soil Bacteria Activity and Diversity

Scientists have thought for decades that such a response is due to individual microbial taxa growth rates in warmer climates. As part of the study, the scientists looked into a subarctic grassland in Iceland that has gone through geothermal warming for over 50 years. This experience led to higher soil temperatures than the surrounding areas.

By gathering soil cores and maximizing cutting-edge probing techniques for isotopes, the researchers could distinguish active bacterial taxa. They then compared the growth rates in ambient and elevated temperatures, with a temperature difference of 6 degrees Celsius.

Dennis Metze, the study's primary author and a PhD student, notes that they saw over 50 years of consistent warming of the soil heightened community-level microbial growth. However, microbe growth rates in warm soil could not be distinguished from those in regular temperatures. The key difference was the diversity of bacteria, as warmer soil had a wider array of active microbial taxa.

Christina Kaiser, an associate professor from the Center, shares that knowing the complexities of the reaction of the soil microbiome to climate change has been quite challenging.

The new study goes beyond the conventional focus on growth that is community-aggregated. It also sets the stage for better microbial behavior predictions and its resultant impacts on carbon cycling in the evolving climate scenario.

The findings shed light on the different responses of microbes to global warming. Such insights are crucial for forecasting the impact of the soil microbiome on future carbon dynamics.

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