Photo: ČT24
Entomologist Kateřina Sam is on the 2023 Forbes list of top Czech female scientists. She has been working on an experimental study aimed at mapping the interdependence of birds and insects and how their disappearance may affect the landscape and in turn humankind in different parts of the world. I recently had the chance to speak to her about her work.
“The project is important because we previously observed that insectivorous birds are missing from some of the tropical forests. When the forests are disturbed the abundance and diversity of these birds goes quickly down. So we wanted to study what would happen if the birds were to disappear completely. We built cages around selected trees, so as to simulate their disappearance.”
Where did you do this?
“We did this at several study sites across the globe –in Japan, Germany, China, in Papua New Guinea and at two study sites in Australia. However, some of the results are only just being analyzed now. We recently published the results of the study in Papua New Guinea. There, the situation was quite specific because we worked around Mount Wilhelm which is the highest mountain of Papua New Guinea and we worked at study sites which were 3,000 meters above sea level and as low as 200 metres above sea level. So a 30 km long elevation gradient.”
And were your findings a particular cause for concern – what did you find?
“In Papua New Guinea we found that the abundance of arthropods increased by dozens of percent. Typically we have around 20 arthropods per square meter of foliage, but when we excluded the predators their numbers doubled, sometimes even tripled, which is a problem for the plants because tropical plants are really sensitive to herbivory damage and when the arthropod communities increased they were causing much higher damage to the trees. The herbivory damage increased by roughly 10 to 20 percent on average. This damage might be critical for small saplings –they could die in the next season or the course of several seasons. That affects the restoration of forests. Because when the forest is selectively logged, the birds disappear, because they don’t like partially logged forests. These areas get lighter and warmer and the birds leave. When that happens the number of arthropods increases and the number of insects increases and they cause more damage to the small saplings. So the restoration of the forest does not happen naturally or it is lower than what we would like to see.”
See the rest here.
Author: Daniela Lazarová