The bioindicator study of South Karelia has been completed
Air quality has been monitored in the municipalities of the South Karelia region since the 1980s approximately every 10 years. In 2022, the air quality was assessed based on pine epiphytic lichens and the survey was carried out in the areas of the municipalities of Imatra, Lappeenranta, Rautjärvi, Ruokolahti, Taipalsaari, Lemi and Savitaipalee. A third of the areas of the observation network had to be changed to a new one due to deforestation, among other things.
In the longer term, emissions in the South Karelia region have clearly decreased from the situation at the end of the 1980s. The concentrations and depositions of pollutants measured in the air have mainly decreased compared to before. The largest emission sources in the study area are located in Lappeenranta and Imatra.
The indicator values of trunk lichens in South Karelia had somewhat weakened compared to the previous survey time. The lichen flora was the most impoverished and damaged in the surroundings of industrial centers and urban areas.
- The areas of Imatra and Lappeenranta stood out as the most impoverished and damaged, he says environmental expert Tiina Osmala From Eurofins Ahma Oy.
Despite the downward trend in air pollutant emissions, the changes in lichens may indicate a deterioration in air quality. Various natural factors, such as rainfall, drought or intense heat, can also affect the results by buffering or intensifying the effects of air pollutants, which is why the responses of bioindicators do not always unambiguously follow the changes in emission amounts.
According to Tiina Osmala, the decline in the condition and diversity of lichens may also be caused by broader factors, such as climate change and its consequences.
For more information:
Environmental expert Tiina Osmala
p. 040 660 7414
Environmental inspector Arto Ahonen
Environmental action of the Imatra region
p. 020 617 4392