Hoppa direkt till innehållet
Publicerad: 26 aug, 2019

How the thawing of permafrost may effect the climate

PORTRÄTT Ellen Dorrepaal studies how frozen soils and open tundra plays a critical role in our climate system, and how interactions between plants and microbes are key drivers of the feedback when permafrost soils thaw or forest moves into the arctic tundra. She will describe in more detail at the Arctic seminars tour on 27 August.

Watch the lunch seminar live stream

27 August at 12:00 - 13:00

What are you going to talk about?

I will talk about two mechanisms by which the arctic plays a critical role in our climate system, by means of feedbacks from natural arctic ecosystems. I will thus explain how frozen soils (permafrost) and treeless tundra do this, and how interactions between plants and microbes or between different plant groups are key drivers of these feedbacks, when permafrost soils thaw or forest moves into the arctic tundra.

Why is your research important?

Permafrost ecosystems store about twice as much carbon in organic form as is currently present in the atmosphere as the greenhouse gasses carbon-dioxide and methane, and warming and thawing of permafrost might cause a huge release of such greenhouse gasses if microbial decomposition is stimulated by the higher temperatures. Treeless tundra is white when it is covered by snow and reflects therefore much more sunlight than when taller trees protrude through the snow and create a darker landscape surface. Our research aims to unravel how interactions between plant roots and microbes control how permafrost thaw will affect microbial decomposition of the soil carbon, and how the dominance of mosses at the treeline affects the impact of climate warming on tree establishment.

What are the most important results so far?

We showed that microbial community changes that are driven by changes in the ecosystem and by different plant species can be a major driver of the temperature sensitivity of decomposition, while they have so far been ignored in large-scale climate models. We also showed that climate warming or changes in winter snow conditions enhance tree establishment in the tundra more when certain moss species are present than other, and that this depends on specific, functional characteristics of these mosses.

How can your research contribute to sustainable development in the Arctic?

Our research contributes to a better understanding of the natural feedbacks from the arctic to the changes in climate that we as humans are causing, and ultimately to better estimates of our future climate under different emission scenarios. Hopefully such understanding will help convince worldwide governments and citizens to increase their efforts to eradicate their climate impacts.

What’s the next step in your research?

A major unknown in our understanding of arctic ecosystem processes and feedbacks to the climate is what happens under the snow during the long arctic winter. Although the arctic climate in winter is harsh, under insulating snow, several plant and soil processes might still continue and contribute to the annual climate feedbacks. Our upcoming research aims to quantify and understand the importance of the winter period better.



Ellen Dorrepaal
090-786 53 21