Study shows that lichens indicate air quality
A student theses from Hasselt’s PXL University College reveals the remarkable ability of lichen growing on trees to indicate polluting substances in the surrounding air
Agricultural zones less polluted than expected
The Hasselt student examined whether lichens can function as biological indicators for the detection of air pollution, specifically to detect the presence of substances like ammonia and sulphur dioxide. He analysed lichens on trees at 16 locations in Limburg – four natural areas, four agricultural zones, four industrial zones and four residential zones – and discovered that lichens provide much information on the substances in the air.
“We noticed an increased concentration of ammonia in areas where a lot of vehicles pass, like industrial zones,” Vanloffelt told Metro. “Motorised traffic is thus partly responsible for the air pollution there.”
The student expected that the lichen would prove that pollution due to pesticides would be high in agricultural areas, but this turned out not to be the case.
Vanloffel did, however, find increasing pollution in residential areas. “There is also a lot of traffic in built-up areas,” he said. “The herbicides and other substances people use in their gardens further add to the pollution.” The lichens can help researchers to follow up the evolution of this pollution.
