Yes there is and I think its fair to say that classical composers never paid it much attention. A pity as many of these old folk songs are truly beautiful! I had an idea to take that up many years ago and I made some compositions which are very inspired by Swedish folk songs but as often, I cannot take the time needed and then I'm not sure I am talented enough to pull it off.
Comparing with Norway, it differs a bit but to be honest, not that much. We live very close and have almost the same language (we understand each other pretty well), share many parts of history and people move and work between our countries without restrictions.
Thanks Robert. There must be 'real' Swedish folk music but I think composers never took it at face value like Norwegian composers did (Grieg with the Slatter, Tveitt with the Hardanger Tunes). But it's probably not fair to always compare Swedish to Norwegian music. The Swedes have a mind and culture of their own.