Berg (mountain) is very popular in names here. "roth" could be the same as Swedish "rot" (root).
There are many Swedish Berg-names: Berggren, Bergkvist, Bergman, Bergstrand, Bergström, Bergvall etc. But I don't know any Bergroth, so it could be German.
"You sought a flower and found a fruit. You sought a spring and found a sea. You sought a woman and found a soul. You are disappointed."
"It does not become me to make myself smaller than I am." (Edith Södergran 1891-1923)