Does APIS hold data about lichen sensitivity to nitrogen oxides?

Lichen are recognised as being sensitive to concentrations in air of pollutants (nitrogen oxide and ammonia) as well as their deposition. APIS has a dedicated page for impacts of air pollution on lichens and bryophytes (mosses).

There are critical levels set for lichens for some pollutants (SO2 and ammonia) to quantify when the pollutant concentration in air is expected to affect lichens. Critical loads relating to effects from nutrient nitrogen deposition have not been outlined for individual lichen species at this time.

In a brief search of the APIS website for "lichen" and "deposition", the following page was identified ( ). It indicates a proxy critical load for woodland could be helpful for lichen growing on trees. A similar approach might be taken for lichen growing on the ground or in wet conditions (eg assign critical load from the habitat the lichen is growing in - bog, heathland or grassland).