If there's enough moisture, they survive.
I was so happy to find that branch on the ground, fully covered by lichen. I mean how many occasions are there? It was so good to sit down and take a hundred photos from different angles, change settings, apply filters and so on. You can't do that outside. People would have looked at me with suspension. Not to mention the mud 😂
Well, lichens usually thrive on dead wood rather than living trees so I think finding a branch covered with lichens is not that unusual, I see many of them in forests and even in city parks. It just never occurred to me to actually take such branch home for further inspection and photo shooting, that´s what I found cool about your experiment :)
Now you know 😏