SIESTA Project: Svalbard summer 2025 expedition report.

Area of Science:

• Glaciology
• Microbiology
• Environmental Science

Background:

• Microbial dormancy is crucial for survival in extreme environments like glaciers.
• Microbial activity impacts biogeochemical cycles and ecosystem resilience.
• Glacier surface environments present unique challenges such as low temperatures and nutrient limitation.

Purpose of the Study:

• To resolve microbial activity and dormancy at the single-cell level on glacier surfaces.
• To characterize adaptive and functional traits of active and dormant microbial populations.
• To link microbial metabolic states to ecological and biogeochemical dynamics in glacial environments.

Main Methods:

• Field expedition to Brøggerhalvøya, Svalbard, in July 2025.
• Sample collection from Midtre Lovénbreen and Austre Brøggerbreen valley glaciers.
• Field and laboratory analyses to assess microbial activity, dormancy, taxa, and functions.

Main Results:

• Site characteristics and sample collection details are reported.
• Initial data provide insights into the spectrum of microbial activity and dormancy.
• Future analyses will reveal taxa and functions associated with active and inactive microbial fractions.

Conclusions:

• Understanding microbial dormancy is vital for glacial ecosystem functioning.
• This research will deepen insights into the role of microbial dormancy in glacial environments.
• Findings will contribute to understanding ecosystem responses to environmental change.