Climate change forces birches to adapt to new conditions

Led by Professor, Vice-Dean Elina Oksanen at the Department of Environmental and Biological Sciences of the University of Eastern Finland, the project was launched 18 months ago and is currently conducting growth chamber experiments at the Kuopio Campus. The project secured funding from the Academy of Finland’s Arctic Academy Programme, seeking to carry out increasingly efficient Arctic research by making use of plant imaging techniques, among other things. The project’s partners include researchers from the University of Helsinki, the Natural Resources Institute of Finland in Vantaa, and the National Research Council of Italy.
“We study the internal, genetic modification of birch species and how different birch species are able to adapt to climate change. This project brings together experts from a variety of fields,” says Senior Researcher Sari Kontunen-Soppela.
“It is important to study birches in the Arctic area, as there are fewer different species there,” says Project Researcher Sarita Keski-Saari.
The currently ongoing experiments analyse silver and downy birches from southern and northern parts of Finland, as well as from Florence in Italy. The birch seedlings have been tissue cultured and they come from natural growth sites.
“We have two growth chambers in Kuopio, and the results will also be used in upcoming field experiments in Italy and in southern and northern Finland.” In Italy, the duration of the photoperiod in the summer is 8.5 hours, whereas in northern Finland, the sun doesn’t set at all. This phenomenon is known as the midnight sun.
“Plants measure the length of the night. In our growth chambers, we modify the photoperiod, i.e. the length of the day, while keeping other conditions such as humidity and temperature steady throughout the entire experiment,” Kontunen-Soppela explains.
“We are interested in finding out whether northern birches can utilise the midnight sun and keep photosynthesis going even at night,” Keski-Saari says.
“Chlorophyll fluorescence allows us to see, indirectly, the photosynthesis of plants. We measure variation in daily photosynthesis under different photoperiods. The birch is a pioneer species that needs plenty of light in order to grow rapidly. In other words, it turns light into chemical energy and uses this energy to grow,” Kontunen-Soppela says.
The study seeks to analyse whether birches originating from specific places are acclimated to their original conditions only, or whether also birches from Italy can make use of the midnight sun.
“Too much light is a stress factor for plants and they need the night time to repair light-induced damage, among other things. We want to know whether the plant is able to repair damages even when the sun doesn’t set. Throughout the experiment, we also analyse the number of leaves and height growth,” Keski-Saari explains.

Climate change makes days warmer, not longer

Findings from the currently ongoing experiments aren’t available just yet. However, earlier studies have shown that when northern and southern seedlings are planted on the same field, the growing season of the northern seedlings ends earlier than the growing season of the southern ones.
Source:University of Eastern Finland