An indicator of environmental quality
The lichen-rich tundra has proved very useful for studying the spread of pollutants around the world: the wind carries pollutants everywhere, even distances of thousands of kilometres. Lichens are good bio-indicators, i.e. they are organisms that allow us to recognise when the balance of the environment is deteriorating.
Air pollution can be controlled by studying lichens, which are special organisms, the result of a symbiosis between an alga (an autotrophic organism) and a fungus (a heterotrophic organism); together they can cope with difficult climatic and environmental conditions and colonise inhospitable places. Symbiosis is an association between different organisms that is beneficial to both. In the case of lichens, the fungus provides water and mineral salts to the algae, also protecting them from excessive desiccation and strong light rays. In return, the alga produces carbohydrates by photosynthesis and shares them with the fungus. Living in very nutrient-poor environments, lichens absorb everything they can. Unfortunately, they also assimilate harmful substances that can lead to their death over time. Analysis of lichens can provide interesting information on the presence of pollutants in the environment.
Reindeer are also good bio-indicators, because they feed on lichens. Researchers follow reindeer as they look for new pastures and check their health.