Vegetation model as a time machine
However, Christoph Schwörer doesn’t just want to find out how the composition and spread of the plant species has changed over the past millennia. He is particularly interested in the future. For this purpose, he uses a vegetation model developed at the ETH Zurich – which he feeds with reconstructed data from the past.
“The model serves as a kind of time machine,” he explains. “If it is able to show the effects of the temperature fluctuations over the past 12,000 years, we can also project the future effects of climate change on the vegetation.”
The Bernese researcher is very familiar with the so-called LandClim model. He worked with it during his two-year stay at the University of Oregon in Eugene, where he did his Swiss National Science Foundation (SNSF) Early Mobility postdoc. In his second postdoctoral position at the Oeschger Centre, he is currently developing a very local but more precise view of future vegetation by means of model simulations. In one of his studies, he has simulated changes in the species composition and in the tree line around Lake Iffig until the year 2500 – and this within a radius of five kilometres and practically tree by tree. The simplified conclusion of this simulation: The tree line will rise considerably, and beeches will expand at the expense of spruces. But according to Schwörer, there will be fewer meadows and fields in the alpine vegetation zone, as some plants have a problem. They cannot survive at high altitude. The reason? The increase in temperature is much too rapid for humus to form on the rocky subsoil.
Christoph Schwörer is striving for an academic career. So for his next step on this challenging path, he’s applying to the SNSF for an Ambizione project. For this research project he hopes to examine alpine sediment cores with unrivalled thoroughness.
“Since the lake bottoms have a maximum temperature of 4°C, the DNA is preserved in plant remains. After the last ice age, plants were forced to shift their distributions due to climatic changes. I want to find out what happens to genetic diversity during these times.”
(December 2016)