_MG_3961 lichens on gravestone 1995-2011

_MG_3961 lichens on gravestone 1995-2011

Observation - _MG_3961 lichens on gravestone 1995-2011 - UK and Ireland. Description: Same gravestone photographed in mid july 1995, Dec 2011 and April 2018 to show change in lichen comm

Same gravestone photographed in mid july 1995, Dec 2011 and April 2018 to show change in lichen communities. Is the black one the same species in same place? The first image is 1995, next two 2011 and last two April 2018(this has fairly close up image of the black species)