Lichens were tested to measure air pollution levels in different areas of a city. The study found that lichen diversity and coverage decreased with proximity to polluting sources like roads, factories, and houses. The most polluted area tested was Statybininkai Street, nearest to pollution sources, with 70% coverage of one lichen species and high SO2 levels over 100%. The least polluted area was Revuona's Park, furthest from pollution, with diverse lichen species and 50% coverage. The results show that lichens can effectively indicate air pollution levels and human activities that produce SO2 are the main polluters.

1. Air pollution
Test of air pollution by lichens

2. Aim of work: To measure air pollution according to the plurality
and composition of lichens’ species.
Hypothesis: The level of air pollution is bigger near the objects
which pollute the environment greatly (roads, factories, houses
etc.).

3. Test of air pollution by lichens:
Type
Researched
of Type of lichens Plenty Coverage, % SO₂ Zone
place
tree
1. Xanthoria parientina ++ 10
Vytautas
Lime 2. Hypogymnia physodes ++ 10 To 70 3
street
3. Paramelia sulcata ++ 37
1. Xanthoria parientina ++ 9
Martišius
Lime 2. Paramelia sulcata ++ 26 To 70 3
street
3. Hypogymnia physodes ++ 26
Revuona’s 1.Pseudevernia furfuracea ++ 50
Lime To 50 2
park 2. Hypogymnia physodes ++ 49
1. Hypogymnia physodes ++ 46
Kaunas street Lime To 70 3
2. Xanthoria parientina ++ 34
1. Xanthoria parientina ++ 70
Statybininkai
Lime 2. Hypogymnia physodes ++ 10 To 100 4
street
3. Pseudevernia furfuracea ++ 12

4. Lichens coverage %
Xanthoria parientina Hypogymnia physodes
70
49 50
46
37
34
26 26
10 10 10 12
9
0 0 0 0 0 0 0
Vytautas street Martišius street Revuona’s park Kaunas street Statybininkai street

5. SO₂ concentration %
SO₂ concentration %
100
70 70 70
50
Vytautas street Martišius street Revuona’s park Kaunas street Statybininkai
street

6. Conclusions:
1. We have found these lichens: . Xanthoria parientina, Hypogymnia
physodes, Paramelia sulcata, Pseudevernia furfuracea.
2. The degree of coverage fluctuates from 9% to 70%.
3. The most polluted area was Statybininkai street, which means that it is
the closest area to polluting objects. The least polluted area was
Revuona’s park, which means that it is the furthest area from polluting
objects as cars, industries and houses.
4. Human beings are the ones who produce the most SO₂.