Okay, I read a story someone linked here a while back and I'm trying to remember the title.

The story was structured as an old school web forum where people were discussing the meaning behind certain lines of an ancient poem.

The poem described a malevolent force in the woods associated with a particular kind of tree that would, cyclically, take people from the town.  Maybe oak?  Ash?

I think that the person taken was turned into wood in after being lured in by a beautiful girl.

One user on the forum was trying to trace the historical roots of the poem and managed to find the town he believes was the one referenced in the poem.  They had a yearly festival that included cutting down all the trees of that type and burning them.

In the end, they guy researching is presumably taken by the forest, after some events outlined in the poem begin to happen again and then he stops posting.

Any guesses?

Edit: I found it. Managed to piece together enough memories to get there. Title was "Where Oaken Hearts do Gather" https://www.uncannymagazine.com/article/where-oaken-hearts-do-gather/