Climate change to force species migrate north

The habitats of different species in the rivers of Finland will move northward as the climate change is causing the temperature to rise.

In addition, seasonal fluctuations in river flows will become more irregular in the future. Small headwater streams will experience greater changes in terms of habitats of species than larger rivers, reports a study conducted by the Finnish Environment Institute and the University of Oulu.

According to the climate change scenarios, the rise in air temperatures at the end of the current century will be the greatest in the northern areas of Finland. The expected composition of fauna living at the bottoms of rivers reflects the changes in temperature.

“According to the forecast, the range of various species will be spreading northward, and as a result of this, the diversity of species in northern rivers would increase. On the other hand, some northern species may disappear from their present habitats in the future,” said Dr. Kaisa-Riikka Mustonen, a researcher at the Department of Ecology and Genetics, University of Oulu.

Clear changes were noticed in the forecast on river flows and the seasonal variation became more difficult to anticipate. The greatest change in the array of species would occur in the waterways where the flow changes the most. Small headwater streams are especially susceptible to changes in water flows and consequently to changes in species living in them.

“It is clear that climate change will alter aquatic nature. Changes in temperature and in the amount of precipitation will affect many functions of the catchment areas of the rivers. In addition, the effects of land use and other human activities will combine with those of climate change. In the study on the impacts of climate change on waterways, we need to take into account various factors and their combined impacts more widely,” said Heikki Mykrä, a special researcher at the Finnish Environment Institute.

Mykrä said climate change poses challenges to the protection and management of waters. Shades need to be maintained, especially in small water bodies to keep the rise in water temperature as low as possible.