I found a few Lygodium vines in the north tract today inside near an area where roofing material was dumped (I should say near ONE of the areas where roofing materials had been dumped). I quickly got a shovel and dug up the plants, bagged them and removed them. It was japonica, which seems to be most of what we get in this part of the county. The Lygodium was near some newly sprouted cogon grass, which had come up in the dirt clinging to the roots of a downed tree. As they say, any disturbed soil. It was removed, too.
This is only the second time I've found Lygodium here. I need to be more alert for it, I suppose.