A little over a month ago I promised to look at how trees have brown or ‘tanned’ looking lichen on their north side in this country (even though buildings tend to have brown mosses and lichens on their south side). This silver birch is a good example of how striking that rusty brown colour can be. It has a strong bias towards growing on the north sides of trees in England. The only reason I have for that is a likely preference for moist conditions. Lichens are wonderfully complex organisms. Any plant or animal is likely to have hidden depths and take time to fully comprehend, but lichens take this to a new level. In a conversation with Rob, the local Forestry Commission manager, he was quite candid:
‘Yes, I’ve noticed that growth too, but to be honest if you want to know more you need to talk to lichen people, there are a few that specialise in nothing else and they are the only ones who really understand lichens.’
The reason for their complexity is that they are symbiotic, they are an association of algae and funghi, which take on about 15,000 known forms. In fact the debate still goes on within the scientific community about how they should be classified at all. Sometimes maybe there is more joy to be had in just looking at nature and not trying to get too clever!