Field Course Piora, Lake Cadagno-’Microbial hydrobiology: Microbial ecology and alpine ecology

7-11 July 2025

Dr Nicola Storelli and Mauro Tonolla SUPSI/UNIGE

Dr Nicola Storelli and Mauro Tonolla SUPSI/UNIGE

Samuele Roman, SUPSI/CBA

Matthieu Bueche, UNINE

Francesco Di Nezio and Gianluca Corno, CNR-IRSA

Anupam Sengupta, Université Luxembourg

This 5-day activity aims at offering the students the required training by combining field activities with the development of a practical project that can be accomplished in the field. This will be complemented by presentations and discussion (by the students and participants) related to topics linked to the environment under study (Lake Cadagno and its catchment area in the Piora region, Tessin).

The field course takes place at an altitude of 2,000 meters in the heart of the Alps at the Center for Alpine Biology (CBA) and lasts five days (7-11 July 2025), with sampling from various aquatic ecosystems such as the Meromictic Lake Cadagno and the adjacent peat bog.

In the context of microbial hydrobiology, the different layers of aquatic systems represent a unique ecological niche with specific environmental conditions, such as temperature, light, nutrient availability, and oxygen levels. These variations create gradients that determine the distribution and activities of microorganisms.

In Piora Valley, two particular stratification phenomena can be observed, one about 20 meters long (Lake Cadagno) and the other about 2.0 cm long (bacterial mat). Lake Cadagno is composed of two layers of water that never mix, thanks to the crenogenic meromixis produced by the geology of the valley. The lower layer, the monimolimnion, has the peculiarity of being completely anoxic and therefore favors the development of ancestral anoxygenic microorganisms. The focus will be on photosynthesis at the chemocline, primarily on the community of anoxygenic phototrophic sulfur bacteria in the lower part, in addition to the microalgae community in the upper part. Bacterial mats in marshes are a fascinating small-scale stratified system. Four layers with extremely different metabolic characteristics are generally found. Here too, the focus will be on photosynthesis, which will be highlighted using microsensors for measuring oxygen (O₂) and hydrogen sulfide (H₂S).

The practical part will be complemented by theoretical presentations on various topics and discussions (by students and participants) on issues related to microbial hydrobiology.

Laboratory analysis

·         physical-chemical profile of the water column of Lake Cadagno using a multiparameter probe (CTD);

·         chemical analysis of surface water in the peat bog;

·         analysis of samples taken using flow cytometry, microscopy (optical and epifluorescence), UNISENSE microsensors, chemical analysis (Specrtroquant Merck) and mathematics (internal waves).

Piora

Reimbursements for CUSO PhD students: Train ticket, 2°class, half-fare from your institution to the place of the activity

Reimbursement of your travel tickets can be asked online through your MyCUSO

Food and accomodation during the course are included for all participants

Registration open

Deadline for registration: 30.05.2025

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