Native cold vs invasives?
One thing about hitting our native cold temperatures only now
and then is that invasive non-native plants and pests that moved in
during a period of warm years may not be able to handle it.
It helped the Russians beat Napoleon and then the Germans! Maybe it will help slow the emerald ash borer's
spread to the north.
However, it is probably only a hope. European cinch bugs, for
instance, moved north during the last 30 years. We'd love to see
them die, die die! So too bad the soil was insulated against our
recent -17F, because those pests overwinter in the soil.
"...people are all giddy about dead, frozen (emerald ash borer)
larvae. Personally, I bet there isn't much mortality except maybe
in northern Minnesota..."
- Deb McCullough, entomologist, emerald ash borer project,
Michigan State University -