I am disappointed that the word “Swidden” is not feeatured in Etymonline: a word denoting an area cleared for cultivation by burning is handy in many situations.
That my surname means exactly that, in Norwegian, is entirely coincidental.
Best regards
Tore Svenning
PS. there is also a given name, Svenning, with a completely different origin - it comes from “Sveinung” which means young man, lad and similar.