Lichens are plant-like organisms that are found on crusty patches of rock, tree trunk and walls. Lichens absorb water and minerals form rainfall and directly from the atmosphere,over their entire surface area.
Lichens are used as bio indicators of sulphur dioxide pollution because they are sensitive to sulpur dioxide pollution form burning fossil fuels. Different lichens tolerate different levels of sulphur dioxide in the air. Therefore, the presence or absence of a particular typeof lichen can tell us the level of sulphur dioxide in the air.
The more polluted the air, the fewer lichen species there are.the cleaner the air is,the more lichen species there are.
Comments
No comments have yet been made