Temporal Dynamics of Atmospheric Microbial Communities in the Alps: Insights from 11-Years of High-Altitude Sampling

Temporal Dynamics of Atmospheric Microbial Communities in the Alps: Insights from 11-Years of High-Altitude Sampling

Marie Labat Saint Vincent¹; Patrik Winiger²; Julian Weng²; Stephan C. Schuster³; Christoph Hueglin⁴; Sophie Darfeuil¹; Pauline Bros-Rolere¹; Patrick Ginot¹; Claudia Mohr^2,5; Jean-Luc Jaffrezo¹; Imad El-Haddad²; Aurélien Dommergue¹; Catherine Larose¹

1: Institut des Géosciences de l’Environnement (IGE) CNRS, UGA, IRD, INRAE, Grenoble INP, 38058, Grenoble CEDEX, France

2 : PSI Center for Energy and Environmental Sciences (PSI-CEES), Paul Scherrer Institute, Villigen, 5232, Switzerland

3 : Singapore Centre for Environmental Life Sciences Engineering (SCELSE), Nanyang Technological University Singapore, Singapore, Singapore

4 : Swiss Federal Laboratories for Materials Science and Technology (EMPA), Dübendorf, 8600, Switzerland

5 : Department of Environmental Systems Science, ETH Zurich, 8092 Zürich, Switzerland

 

Atmospheric microbial communities play a significant role in biogeochemical cycles and serve as a key source of microorganisms deposited onto glacial surfaces, where they may be preserved for millennia. Understanding the dynamics of these communities and their responses to environmental factors is critical for assessing their transfer and preservation in glacial archives. In this study, we leverage a unique dataset collected by the Swiss National Air Pollution Monitoring Network (NABEL), consisting of 11 years (2010–2021) of atmospheric particulate samples from Jungfraujoch (3500m a.s.l., Switzerland). This sampling site provides a rare opportunity to unravel atmospheric microbial community dynamics at high altitude as well as providing information on the pool of microorganisms that can potentially be deposited onto glaciers in the Alps.

DNA extraction and quantitative PCR (qPCR) were performed on atmospheric filters collected every four days (>1000 samples) to quantify microbial abundance. These data allow us to investigate the temporal trends in abundance in the Alpine atmosphere over more than a decade, highlighting seasonal variations over time. Additionally, correlations with geo-physico-chemical environmental parameters, like temperature, pollution events, and atmospheric composition, were carried out to identify key factors driving these dynamics.

This time series represents one of the most comprehensive temporal datasets of atmospheric microbial dynamics at high altitude available. In addition to providing a unique opportunity to characterize the drivers of microbial communities in the atmosphere over longer time scales, this data also represents an important step towards understanding the processes governing microbial deposition and preservation in Alpine ice. This work lays the foundation to the broader goal of validating ice cores as reliable archives of past atmospheric microbial diversity and environmental conditions.