Phylloxera damn near wiped out the European wine industry. That's pretty major.
And restocked from America. The idea of "terroir" being a marketing campaign to convince the French that it wasn't the old vines (as previously claimed) but the earth and climate that made the wine.
I hope they manage to contain that chestnut gall wasp. I know there were one or two diseases of chestnut that the FC were worried about, which is why imports of plant material were stopped.