Thank you both for helping me, to get a better understanding of the things mentioned.
I am really glad, that I asked these questions because I learned here something new to me.
I also made Screenshots from your explanations and saved them in my TG folder :-)
I think it's sometimes better to play a little bit with other seeds to prevent those glitches beforehand.
This is something I keep in mind when I stumble upon glitches in future scenes (created with the alpine shader).
But...
In the meantime there has fallen another render from my tree....
Icy Mountains 2023 by Stormlord
STORMLORD