The article discusses a study conducted by researchers at the Centre for Microbiology and Environmental Systems Science (CeMESS) at the University of Vienna, which found that global warming increases the diversity of active soil bacteria. Traditionally, it was assumed that higher soil temperatures would accelerate microbial growth, leading to increased carbon release into the atmosphere. However, the study reveals that the increased carbon release is actually due to the activation of previously dormant bacteria.
Andreas Richter, the lead author of the study, highlights the significance of soil as Earth’s largest reservoir of organic carbon and emphasizes the role of microorganisms in the global carbon cycle. As temperatures rise due to climate change, microbial communities are expected to emit more carbon dioxide, thereby exacerbating climate change through a process known as soil carbon-climate feedback.
The researchers conducted their study in a subarctic grassland in Iceland that has experienced geothermal warming for over half a century, resulting in elevated soil temperatures. By employing advanced isotope probing techniques, they identified active bacterial taxa and compared their growth rates at ambient and elevated temperatures. Surprisingly, while soil warming increased microbial growth at the community level, the growth rates of microbes in warmer soils were similar to those at normal temperatures. The key difference lay in the bacterial diversity, with warmer soils harboring a more diverse array of active microbial taxa.
Christina Kaiser, an associate professor at the Centre, highlights the challenge of understanding the soil microbiome’s reaction to climate change, often considered a “black box” in climate modeling. However, this study provides valuable insights into microbial responses to warming, paving the way for more accurate predictions of microbial behavior and its impact on carbon cycling in future climate scenarios. Overall, the study underscores the importance of considering microbial diversity in understanding the dynamics of soil carbon in a changing climate.
