Soil fungi remain active during drought

Drought significantly affects terrestrial ecosystems, including soil microbial communities. Our study, utilizing an innovative stable isotope tracing method, reveals that while bacterial growth was greatly reduced during drought, fungi maintained stable growth.
Like

Share this post

Choose a social network to share with, or copy the URL to share elsewhere

This is a representation of how your post may appear on social media. The actual post will vary between social networks

Our climate is getting warmer and many regions of the world will experience increasing heatwaves and drought periods. Drought poses a significant challenge globally, impacting both natural and agricultural ecosystems. While the effects of water stress on plants are well-documented, its influence on soils and associated microbial communities remains less understood, despite being one of the most common environmental stresses experienced by soil microorganisms. 

We have both done extensive research on investigating effects of drought in the field and under laboratory conditions, but studying microbial activity in dry soil is notoriously difficult without changing water content or adding an additional substrate. Only recently, Alberto together with some colleagues, have developed a quite  elegant way to trace the activity of microbes in soils using 18O vapor exchange labelling, which finally allows us to study microbial activity, and growth under conditions as realistic as possible. This method allows now to quantify community-level growth also during drought periods. In our recent study, we verified and expanded this method by using deuterium tracing into microbial lipids. With this modification we can now investigate three processes concomitantly: soil microbial community physiological activity, microbial group-specific growth patterns, and the production rates of triglycerides, which are an important class of storage compounds.

We applied this development on the unique experimental setup of the ClimGrass project in the Austrian Alps, led by a multidisciplinary team of scientists. This experiment provides a rare opportunity, as it simulates future climate scenarios through combined warming, elevated CO2, and drought treatments. The project’s design allows for high-resolution investigation of microbial responses in real-world conditions, bridging a critical gap between controlled laboratory studies and field ecology.

Picture of the ClimGrass site showing the climate change manipulations (CO2 fumigation, infrared heaters and rain out shelters).
Fig. 1 Picture of the ClimGrass site showing the climate change manipulations, including CO2 fumigation, infrared heaters and rain out shelters (Copyright of Alberto Canarini).

We quantified microbial growth and storage compound synthesis with an unprecedented level of detail. This approach enabled us to disentangle bacterial and fungal responses to drought, their growth strategies, and their contributions to soil carbon cycling.

Fig. 3 Mass-specific growth rates of different microbial groups. a) Gram-positive
and b) Gram-negative bacterial markers and c) fungal markers, as well as d) the ratio
of fungal to bacterial growth rates at peak drought and recovery (‘Drought’ and
‘Recovery’). 

The results were really surprising. Bacterial growth halved during drought, while fungi displayed remarkable resistance (Fig. 2), maintaining stable growth rates and significantly increasing their investment in storage triglycerides (Fig. 3)— which points out that fungi can benefit from this strategy to endure stressful conditions.

Fig. 3. Fungal investment into storage compounds. a) Production of fungal
specific NLFA during ‘Drought’ and ‘Recovery’ periods. b) Ratio of fungal specific
newly produced NLFA to newly produced PLFA (expressed as percentage), indicating
that fungi increase the relative investment in NLFAs during drought. This
ratio allows to account for a potential underestimation of mass-specific NLFA
production rates caused by potential necromass-NLFA accumulation.

Our findings underscore the adaptive resilience of soil fungi and their potential to mediate carbon cycling under future climate scenarios. It also highlights  that to shed light on mechanisms of soil microbial responses to environmental stress conditions we need to investigate parameters beyond cell replication and including taxa-specific strategies. 

 

Please sign in or register for FREE

If you are a registered user on Research Communities by Springer Nature, please sign in

Follow the Topic

Soil Microbiology
Life Sciences > Biological Sciences > Microbiology > Environmental Microbiology > Soil Microbiology
Climate Change Ecology
Life Sciences > Biological Sciences > Ecology > Climate Change Ecology

Related Collections

With collections, you can get published faster and increase your visibility.

Applications of Artificial Intelligence in Cancer

In this cross-journal collection between Nature Communications, npj Digital Medicine, npj Precision Oncology, Communications Medicine, Communications Biology, and Scientific Reports, we invite submissions with a focus on artificial intelligence in cancer.

Publishing Model: Open Access

Deadline: Mar 31, 2025

Biology of rare genetic disorders

This cross-journal Collection between Nature Communications, Communications Biology, npj Genomic Medicine and Scientific Reports brings together research articles that provide new insights into the biology of rare genetic disorders, also known as Mendelian or monogenic disorders.

Publishing Model: Open Access

Deadline: Apr 30, 2025