needle tree roots bad?

[karinpointner]

I have heard that apparently needle trees are not good to use in terrariums because they release a harmful substance when wet? Does that kind of wood harm orchids too? Specifically I found a beautiful root of a fir tree that I would love to use.
I'd be very happy about some input. Maybe someone has an idea what substance that could be or has experience with an orchid already mounted on that kind of wood?

[Island Girl]

Not sure... I know cedar trees are ok. I'll provide a Bump @ the very least.