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Lichens Go! is a monitoring of lichens growing on trees in cities to better understand the ecology of these organisms and their sensitivity to air pollution.

Specific actions

Locate three straight trees.
Observe the lichens on their trunks and determine them with the lichens GO key! (available on the site)
Enter your observation data and participate in the construction of knowledge on these organisms and on air quality!

Project created
Mainland France

Everywhere in France

Type of project : Field, online

Participation period : case by case

Level of involvement : Case by case



Project description

Join Lichens GO! and discover lichens growing on trees in cities in order to assess the average levels of air pollution and better understand the ecology of these very specific organisms.

An identification key has been developed to allow the recognition of different lichen species without the need for any other material than a botanical magnifying glass! The study method is based on the presence of different lichen species to assess the level of pollution.


How to participate ?


Before going on the field:


Make sure you have all the necessary equipment:

field sheets to record your observations.

– your observation grid to analyze the distribution of the different lichens: to make it, use our template. You can also cut 5 squares of sheep mesh.

– a magnifying glass (magnification X10)

– a compass or a smartphone

– a meter

– an electronic identification key is also available on line!


Are you ready ? So let’s go !


During the field trip:


1) Locate 3 straight trees in town

Note the species of trees, their circumferences, their location as well as their proximity to a building.


2) Place the base of your observation grid 1m above the ground on the four faces (north, south, east, west) of each of the three trees.

The grid made up of 5 aligned squares of 10×10 cm delimits the observation area.


3) Identify the lichen species present using our determination key.

Find this determination key and all the information to implement the protocol in our booklet. You can also determine the lichens you observe with this electronic determination key. Record your observations on the field sheet.


After the field trip:

Create an account on Tela Botanica.

Enter the data from your field sheet online on the platform.

Share your photos and your feedback with the community of participants on the Lichens GO forum! from Tela Botanica.

The participation

Training required


Required equipment

– field sheet
– observation grid to make yourself
– magnifying glass (magnification x10)
– metre
– compass or smartphone




Ingénieure de recherche - Coordinatrice du programme PartiCitaE

Sorbonne University

Observatoires des sciences de l’Univers Ecce Terra

Lena de Vanssay

Lena de Vanssay

Animatrice de la communauté PartiCitaE

Sorbonne University


Lena de Vanssay