You have my sympathies! My PIA invasives are honeysuckle, both vining and shrubby, buckthorn, and Asian bittersweet. I'm afraid I'll never totally remove the buckthorn, but I am trying to keep it from getting worse and slowly picking away at the acres of them that I do have with pliers to rip out the small ones, clippers for the medium-sized ones and a power saw for the biggest. I also have some issues with sheep sorrel and cow vetch, which try to crawl from the field into my gardens. While I do work to remove poison ivy from the areas we frequent (paths, lawn, and areas a cat might go since our last one brought in the oil on her fur and transfered it to the furniture) my PI doesn't hold a candle to yours as it doesn't often climb trees here. I leave it in areas we don't go since it's an important wildlife food.

I do remove purple loosestrife from the river bank when I spot it, but the changing water level and currents make it a less friendly environment for loosestrife than a marsh.

You do have some very impressive weeds, pixie_lou! Bittersweet and poison ivy are major problems here too. The big bittersweet vines (originally planted by my mother many years ago) are mostly out of the yard but are well established on the coastal bank so the seedlings keep appearing up here. Those I can pull out without mercy or itching.

Poison ivy is mostly in the woods across the street and a year or so ago I had a monster root/stem climbing up an oak that looked like yours. I carefully cut a section out of the hairy monster so the top would die off and watched the bottom. Luckily it hasn't sprouted from the ground. That's good because it's very near my compost pile.

I get poison ivy seedlings every year but I make a point of going out after a rain when the ground is soft, with a couple of plastic bags on my hand, pooper-scooper style. They pull out easily when they're small and the soil is wet.

I'm more conflicted about the wild cherry seedlings. I like wild cherries but they're everywhere! More than maple seedlings, which are almost everywhere.

Claire