THE USE OF LICHENS AS BIOINDICATORS OF THE EFFECTS OF POLLUTION

1. THE USE OF LICHENS
AS
BIOINDICATORS
OFTHE EFFECTS OF POLLUTION

2. Lichens:
• are made up of both fungus and algae living
together in one structure.
• are very sensitive to air pollution and so won’t
grow if there are high levels of pollutants.
• are particularly sensitive to environmental
stresses, such as eutrophication and climate
change.

3. • Lichens exist in a lot of species but only in
three different forms. They can be classified
according to the shape of their thallus and
the type of adhesion to the substrate
• crustose
• leafy
• fruticoso

4. • allow to carry out valid and complete
environmental analysis as their ecological
variations reveal different levels of pollution.
• grow on many kinds of surfaces
including trees, soil and rocks (epiphytic
lichens)
Lichens

5. STUDENTS observe, measure, study…..

6. STUDENTS observe, measure, study…..

7. Collection data

8. Observation through magnifiers:
leafy and crustose. Not fructicose found, because much
more sensitive to artificial dust.

9. Geographic data:
position, direction and meteo data

10. LIMITS TO THE STUDY
LICHENS:
1) ARE NOT SUITABLE FOR THE STUDY OF
ENVIRONMENTAL EMERGENCIES, EVEN
IF THEY ARE VERY SENSITIVE TO
ENVIRONMENTAL POLLUTIONS, THEIR
RESPONSE IS SLOW
2) REVEAL THE TYPES OF POLLUTANTS
WHICH WOULD BE RECOGNIZED WITH
APPROPRIATE CHEMICAL TREATMENTS
3) LIVE ONLY ON TREES WITH NEUTRAL
OR ALKALINE BARKS.

11. What is the air quality in my town ?
• Students locate the
three points;
• The results obtained
are valid on a circular
area of 250 meters
ray.

12. • We find the positions of the
trees using the UPS system:
• TREE ZONE 1: X=…….y=……
• TREE ZONE 2
• TREE ZONE 3

13. How to find the coordinates
using the scalimeter

14. We identify the 250 meters area
using the calipers

15. We paint the area…

16. …according to the 7 official colours

17. Conclusions
• In our village the air is worse in
the following situations:
parking areas, traffic lights,
crossroads, slowdowns;
• the trees act as cleaners of the
atmosphere, in fact in the
public park the air is better;
• since there aren’t any industrial
activities, the cause of pollution
is the traffic.

18. Limitations
• Lichens don’t tell us the different types of
pollutants (dust, chemical products, gas, smog)
• Don’t reveal environmental emergencies but
tell us the story of the air breathed in the area
during the last years.

19. THANK YOU FOR ATTENTION!