Hi again, its a ‘yes and no’ answer to that one!
Most important is the bark PH – some corticolous lichen species are restricted to trees with a basic bark, others to trees with acidic bark. Very rough guide Elder, Ash, Elm have basic bark, Birch and pines acidic but the bark PH is also affected by tree age and the soil conditions etc
Then there are others like Xanthoria and Physcia’s that need nutrient enrichment (nitrogen) from exhaust fumes and agricultural fertilisers.
