Lichens living warning system for climate changes
Name: Kristin Palmqvist
Lichens may look small and insignificant. But if we learn more about them, they can function as living warning systems for future climate changes.
Lichens are sensitive to air pollution and changes in the climate. That makes them an important puzzle piece in researchers’ studies of climate changes. We know that lichens are disappearing from many places today, but not really why.
Kikki Palmqvist hopes to be able to solve this riddle. She is conducting a long-term trial in a lichen-rich forest at Kulbäcksliden outside of Vindeln in Västerbotten, Sweden. She has built seven to eight metre high towers around 16 trees to be able to observe what happens to lichens if they are exposed to various types of stress.
“Lichens are good at taking up and storing nitrogen. We know that an increased nitrogen load is significant to their disappearance from large parts of Europe, but because no one noticed anything until it was too late, we do not know what it was that happened. In the test park, we fertilize the trees with five different levels of nitrogen to see how they are affected. We monitor the changes by photographing the lichens and comparing them with earlier photos,” explains Kikki.
They also measure chemical and physiological changes in the lichens to monitor and understand the changes. “In the towers, we can also see if any lichen grows at the expense of another, if they become sick or better to eat and disappear as a result.”
The towers were built in 2005, but effects can already be seen. “To date, we have not succeeded in fertilizing any lichens to death, although we have tried,” says Kikki with a laugh. “In previous short- term tests, we fertilized ten times as much as is done in the Netherlands, and that is a lot. Consequently, the time factor appears
to be important.”
In parallel with the long-term test with fertilization, new short-term experiments are under way.
“That way, we hope to be able to distinguish between the impact of short-term and long-term effects.”
Sweden and Norrland are very well suited for studies of lichens since there are 2,000 different lichens in the country.
“There are a total of 20,000 species in the world. The lichens are important because they come first to areas without vegetation. They pave the way for new vegetation. They are also of significance to biological diversity. Because they are suited to nutrient-poor environments, they are very sensitive to changes. If the lichens disappear, spiders and mites also vanish, which in turn means that birds have no food.”
Lichens are not actually a “species” because they are a symbiosis between several different organisms, most often fungi and an alga, but sometimes fungi and a cyanobacterium.
“That makes them extra exciting. They have many colours and shapes and are very beautiful. One of the most beautiful, I think, is the emerald- green Lobaria pulmonaria. The star-tipped reindeer lichen, or reindeer moss, is also very beautiful. Up close, it looks like a miniature tree.”
Lichens are somewhat uncomplicated organisms on which to conduct research, which means that they work well as model systems.
“This means that we can use experiments on lichens to find answers to questions that apply to more complex organisms,” explains Kikki Palmqvist.
Name: Kristin Palmqvist
Profession: Professor of Plant Ecological Physiology
Leisure activities: Sew in the winter and am out in the garden and
nature during the summer
Likes to read: Nobel laureates and detective novels in English
Likes to eat: Everything my husband cooks
Listens to: P1 (public service radio)
Role model: Dag Hammarsköld and Nelson Mandela