Introductory presentation provided via the OPAL (Open Air Laboratory) project.

1. Lichens and
Pollution …
Is our air clean?
Activities follow the information on the OPAL air survey web pages -
http://www.opalexplorenature.org/
Compiled by Jacqui Middleton, 2010.

2. WHAT IS A LICHEN?
o Lichens are made up of two
different organisms living
together:
A fungus and an alga
.
o The fungus provides the body in
which the alga can live protected
from light and drought.
o The alga makes the food for the

3. Many lichens do not like air
pollution
There are many types of air pollution:
o Smoke from chimneys
o Car fumes
o Dust and fertiliser from fields
o Fumes from factories and power stations
All of these types of air pollution contain
NITROGEN – many lichens do not like too
much NITROGEN.

4. What do our air-monitor
lichens look like?
• Leafy lichens
Parmelia family – brown, yellow-green Xanthoria – Physcia – with
and grey-green leafy lichens – have orange leafy longish hairs
short hairs on their underside lichens on the edges
• Bushy lichens
Evernia - Green top &
White underside Usnea – like a Hypogymnia – a puffy
wirey beard lichen with no hairs

5. Our air-
monitor
lichens will
tell us how
clean our air
is.

6. Looking for our lichens - 1
• We are going to find the 4
best lichen trees in the
school grounds.
• Each group will choose one
tree and measure its girth
using a tape measure (or a
piece of string and a ruler).

7. Looking for our lichens - 2
• We are going to look for the 1 2 3
different lichens on the trunk
of a tree up to our heads .
• We are also going to say how
much of each type of lichen is
on the tree and will tell our
group leader.
• 0 = no lichens
• 1 = enough lichens to cover a
quarter of a sheet of A4
• 2 = enough lichens to cover 1 2 3
half a sheet of A4
• 3 = enough lichens to cover a A4 sheet of
whole sheet or more paper

8. Looking for our lichens - 3
•We are going to look for
lichens on twigs
•We are going to look for algae
(dark green or orange
powder)
•Your group leader will make
a note of what you see on
your group’s record sheet.

9. What do the results mean?
• Places with clean air have
more pollution sensitive
bushy lichens (e.g. Usnea and
Evernia)
• Places that have a lot of
nitrogen will have a lot of the
orange leafy lichens
(Xanthoria)
• Places that have quite clean
air will have lots of the green
and brown leafy lichens
(Parmelias)
• If both are growing together
then the air might be
changing

10. After we come back in …
• The oldest children will set up air
pollution tubes to put outside.
• Everyone else will make drawings
and/or write about what we did to
put up on our display or into our
Wildlife Club display book.
• Please stay with your groups today.
For more information and downloads concerning these activities go to
the OPAL air survey web pages - http://www.opalexplorenature.org/