Thriving in extremes: Local adaptation of grasses (Poaceae) to geothermally heated soils on a subarctic island

Temperature affects life on all levels, from the speed of chemical reactions to how organisms are built and when they reproduce. During the evolutionary history of planet Earth, life has managed to establish itself in broad range of temperatures, ranging from freezing Arctic regions and mountain tops to the scorching heat of lowland deserts. Survival in such drastically different environments depends on a number of adjustments in how organisms are built and function. If such adjustments are beneficial to a specific environment, and can be passed to the next generation, they are called local adaptations. Plants are the fundamental building blocks of all ecosystems on land and provide clean water and the oxygen that we breathe. Understanding plant adaptations to local variations in temperature is therefore crucial for understanding natural processes on our planet. This has become especially important for understanding the effects of climate change, under which temperatures are rising at an unprecedented rate.

Simulating different temperature conditions in experiments is not easy. Therefore, there are many open questions regarding how plants adapt to extreme temperatures and what happens if temperatures are elevated for long periods of time. In this thesis, I took advantage of the natural experiment found in geothermal areas in Iceland, where plants grow on soils that have been permanently heated by geothermal activity over several generations. What also makes these habitats especially suited for the study of local adaptation is that the same species can be found on geothermal soils, which can reach up to 90 °C, and surrounding non-heated soils, which are often very cold in Iceland, rarely reaching more than 20 °C. Only a few species are able to thrive in both of these extreme environments and not much is known about the adaptations that allow them to do so, whether they are specialised to these soils or are generally able to tolerate a broad range of temperatures, where they came from and how they can help us understand climate change responses. The aim of my thesis was to answer these questions and test whether local adaptation is necessary to thrive on geothermal soils.

Read more:

Full thesis is available here
 

Practical details

The venue of this dissertation is the Vivi Täckholm hall but it will also be possible to join online via Zoom. 

Link to presentation (passcode: 600980)
 

Jan-Niklas Nuppenau

PhD student: Jan-Niklas Nuppenau

Supervisors:
Associate Professor Aelys Humphreys

Professor Catarina Rydin 

Professor Johan Erhlén
(All from the Department of Ecology, Environment and Plant Sciences)

Opponent: Professor Alessandro Chiarucci, Department of Biological, Geological, and Environmental Sciences, University of Bologna, Italy.