SSC from above - manmade roof, but nature takes over

I had the idea right away last sunday, but waited until today. Then - surprise surprise - it had been snowing during the night. Fortunately in the afternoon, the snow had melted away (leftovers to be seen at top of the picture).
I did not know that there could be so many different kinds of moss in one place (without even asking if they may use our roof to grow).

This is a part of our roof in Regensburg. I had to do some climbing to take this shot ;-)