Rising temperatures affect wetlands and disrupt the water balance

Degerö Stormyr in Vindeln, Sweden, one of the climate research stations which have contributed with data to the new study. PHOTO: ANDREAS PALMÉN
Degerö Stormyr in Vindeln, Sweden, one of the climate research stations which have contributed with data to the new study. PHOTO: ANDREAS PALMÉN

In a future warmer climate, evaporation from the northern hemisphere’s wetlands will increase significantly more than previously thought. This is shown by an international study involving researchers from Lund University and the Swedish University of Agricultural Sciences.

The availability of water is one of the most vital factors for the functioning of different ecosystems. When water levels fall due to climate change, it affects wildlife, nature and people.

In a new study presented in Nature Climate Change, an international research team examined evaporation from parts of the northern hemisphere characterized by coniferous forest and tundra. The study shows that evaporation from wetlands increase far more than from forested areas in a future warmer climate.

“The higher the temperature, the higher the amount of water vapour that the air can hold before it becomes saturated. As wetlands cannot regulate evaporation as effectively as the forest’s trees, which can close the leaves’ stomata in order to prevent water shortage, the evaporation from the wetlands is much greater when the vapor pressure deficit increases”, says Anders Lindroth, physical geographer at our department.

The data that formed the basis for the study comes from 95 climate stations, 13 of which are in Sweden. Several of the stations are part of the two research infrastructures ICOS and SITES, which are co-funded by the Swedish Research Council and institutions involved in the consortia.

In addition to Lund University and the Swedish University of Agricultural Sciences, 35 international higher education institutions and organizations were involved in the study.

Article: "Increasing contribution of peatlands to boreal evapotranspiration in a warming climate" – nature.com