How Plants Are Reacting to Climate Change
How will the landscape look in Switzerland in 50 years? Ansgar Kahmen, professor of sustainable land use at the University of Basel’s Institute of Botany, studies how our flora is reacting to climate change.
Measurable impacts already
Climate change is expected to bring increasingly frequent dry periods to Switzerland. No one knows just how our meadows, forests and fields will react to this. Plants live in a finely balanced equilibrium with their environment – an equilibrium that can be easily toppled.
Ansgar Kahmen studies changes in how plants behave by measuring the exchange of vital substances between plants and the environment: carbon dioxide, oxygen, hydrogen and nitrogen. These four elements are found in nature in various forms, or what are known as stable isotopes. The reaction of plants to climate change can be measured directly and precisely on the basis of isotope ratios. Before he came to Basel, Kahmen worked at ETH Zurich, the University of California at Berkeley and the Max Planck Institute in Jena on the advancement of measurements with stable isotopes. “What I do is basic research,” he says, “but it is delivering actual usable results.”
Kahmen has found evidence that our vegetation has already reacted to climate change over the last 100 years. In order to study changes in the water balance in various species, he studied plant collections at the institute and the Basel Botanical Society (Basler Botanische Gesellschaft). The Basel-based researcher says that his results will have ramifications for agriculture and forestry. “It’s necessary to consider what triggers climate change so that we can continue to ensure stable yields in the decades to come.”
Greater stability through biodiversity
Our cattle pastures will also change. Scientists have long speculated that landscapes with large biodiversity are better equipped to handle extreme weather changes. Kahmen and his team presented impressive evidence to support this hypothesis by measuring the yield of pastures of varying composition. Based on his work, the seed for pastures should be diversified to ensure Swiss milk cows have enough to eat even during dry spells.
Sustainable research as part of Basel’s botany tradition
The plant research projects are being conducted as part of the focal area for sustainability and energy research at the University of Basel. According to Kahmen, plants are important and much more than a source of revenue for the agricultural sector: “They prevent the soil from eroding, balance humidity, provide clean drinking water and many more of the things that we humans need to live.” Plants even have a dampening effect on climate change by absorbing a fourth of excess carbon dioxide released by human activities worldwide.