Lichens GO
Assess air quality in urban areas
Lichens GO is a citizen science program that aims to assess the air quality around your home by studying the different species of lichens that grow on trees. These organisms having a slow growth, they indicate a level of pollution accumulated over several years, which makes them complementary to measurement sensors.

With the data collected in the field, you will be able to participate in the air quality mapping in your city. In addition to contributing to scientific research, it is an opportunity to learn more about air pollution and its impact on biodiversity.
Lichens GO is an observatory of PartiCitaE (Sorbonne University) and Vigie-Nature École (National Museum of Natural History). It is offered in partnership with Tela Botanica (as part of the project Auprès de mon arbre) and UCLouvain.
Financial support
What is a lichen?
Often unknown to the general public, lichens are good bioindicator present all around us. There are more than 20,000 species worldwide. Lichens have the particularity of being made up of two organisms: a heterotrophic fungus and an autotrophic alga or cyanobacterium.

In this association, the fungus constitutes the dominant part of the lichen body, also called the thallus. It provides water and mineral nutrition captured from the atmosphere (rain, fog, etc.). In return, the alga or cyanobacterium carries out photosynthesis, producing the energy necessary for the lichen growth. This type of mutually beneficial association is called symbiosis.

Lichens and air pollution
Unlike plants, lichens do not have roots. They uptake all the nutrients from the atmosphere, which makes them sensitive to air pollution. However, not all lichens are affected in the same way by pollution: the same pollutant can be harmful for one species and beneficial for another.

By studying both diversity and abundance of lichens that grow on trees, it is possible to assess air quality without employing chemical or physical sensors. Due to their slow growth, lichens integrate pollution over several years, making them good indicators of air quality.

I participate!
To participate to the Lichens GO project, you have to follow the different steps of the protocol as indicated below.
Documents for the field
To start in the field, you can download the full protocol with the identification key, as well as the field sheet.
More information?
For more information, you can download the slides of the Lichens GO conference and formation.
Lichen identification
If you need help to identify lichen species, you can use the online identification key:
If you are not sure of your identification, come and share your photos on the Lichens GO project of the iNaturalist exchange platform:
For more information, visit the Lichens GO Facebook group:
Data entry
Enter your observation data easily via the platform:
Data entry
What is the air quality near you?
Using the collected data, it is possible to calculate multiple air quality indices for each sampling site. These indices will allow to generate a map of air quality of your close environment. The more data we collect, the more accurate this map will be!

Soon, you will be able to see the first results of the Lichens GO! project in this section.