According to this AP article from The Seattle Post-Intelligencer, the forests of Oregon, so recently in danger from massive fires, are now in danger from noxious weeds. Apparently weed recruitment is high in the recently burned areas, and some are worried that the forests will not be able to recover. There is additional concern that the weeds will spread across the country via equipment from other states used to fight the fires. Sounds pretty ominous, but I can't tell for sure, since the article doesn't mention a single plant species. Oregon's certainly got a lot to choose from, though, as you can see from this list.