Apping and assessing air pollution using lichens!

CEH released a new mobile phone app today. It gives everyone a way of assessing nitrogen pollution in their local area.

For those that don’t know lichens look like this!

The app is based on a field guide developed by CEH staff and our partners last year

Unlike most of our previous apps, such as iRecord Butterflies and iRecord Ladybirds, the Lichen app isn’t for wildlife recording, rather it’s a tool for assessing the status of nitrogen in your area by surveying lichen on trees. By identifying the presence or absence of nine nitrogen sensitive and eight non-sensitive lichens on tree trunks and branches you can get an estimate of how polluted your area is.

Lichens on a tree trunk – © Ian Leith/Centre for Ecology & Hydrology

Full guidance can be found in the app but basically to get going you need to Identify five oak or five birch trees (not a mixture of the two) in your local area.

• Trees should be single stemmed (standard) with a straight trunk, and greater than 40 cm in girth. 
• There also needs to be some accessible branches.

Following the instructions in the app you then identify the lichens growing on the East, West, South of the tree trunks, and then some of the tree branches. You might need to use a hand lens to help with ID as some lichen features are very small!

Here's where you need to sample lichens on your trees.

All the details are then recorded using the App:

And if you have any problems identifying your lichens there’s a handy ID guide built into the App with lots of photos:

Once all the info is complete, you click on the ‘Results’ button. The app works out your lichen indicator score (LIS) and the NAQI score (Nitrogen Air Quality Index).

That’s it! More information on the Lichen App can be found in a news story on our website.

Related links

New app to monitor air quality using lichens - CEH news

Download the Lichen App

Lichen field manual