Bom dia, my name is Sebastian and I am a biologist participating in the ATTO project since 2017. At the moment I am working on my master thesis on “Bioaerosol emission patterns of tropical fungi in the Amazon”, under the supervision of Bettina Weber and Christopher Pöhlker. Bioaerosols are particles in the atmosphere originating from a biological source, for example fungal spores, bacteria and viruses.The fungal spores are what interests our research team. They account for a large fraction of big particles in nearly any kind of ecosystem, especially in the Amazon Basin. Fungal spore emissions can be extremely high. We measured up to 3 billion spores a day! Sometimes they are even visible with the naked eye. Together with multiple colleagues, in particular Nina Löbs and Cybelli Barbosa, I developed a measurement setup, with which we can quantify and analyze fungal particle emissions in the field and in the lab.
The most important part of this setup is a particle detector called “Optical particle sizer” (OPS model 3330, TSI Inc., Shoreview, Minnesota, USA). It can detect tiny particles between 0.3 and 10 µm. This is perfect, as fungal spores normally range between 2 and 10 µm in size. For comparison, a grain of flour is ca. 150 µm in size. The OPS has an internal pump to suck in the environmental air. In the airstream the number of particles and their size is measured. A photodetector measures the light scattering of the particles when they are hit by an internal laser beam. With the different light reflection pattern of the detected particles, the OPS can determine their size and concentration in real-time. For the measurements we are using two OPS. With one we measure the fungus directly in the field. With the other we perform measurements in the lab, where spore emissions can be analyzed under controlled conditions. In this newly developed chamber system its possible to separate particle emissions of the fungus by aerosols of environmental air.
As mentioned above, we measure the fungi directly at the location where they grow in nature. This requires a lot of work to install the setup in the field between the trees, plants and dangerous animals. Thus, currently, our work is basically to go into the deep Amazonian forest and find a fruiting fungus. We carry all the equipment there, which includes the OPS and Datalogger for humidity, temperature and pressure, as well as a big metal box that protects the instrument of rain. And as our instrument needs a permanent energy source, we also need to connect it with a really long power line and connect it to the next energy source. Only then can we start the measurement. During a field campaign we do this every day.
One challenging part of this work is to permanently keep track of all the dangerous animals while walking through the understory. In more than two years of work we already watched big spiders, deadly snakes and even had a jaguar crossing our path. Despite all these hazards of our work, the pure fascination of this unique environment and the curiosity and passion for nature still catches me every day. I can’t wait to go back to the ATTO site in the middle of the Amazon.