----- Original Message -----
From: "Lee Frelich" <[email protected]>
To: <[email protected]>
Sent: Wednesday, January 06, 2010 6:13 PM
Subject: Re: [ENTS] Impact of cold snap?
James:
I don't think so. Emerald ash borer survived last winters cold spell in
Minnesota, which was much colder than the current cold spell.
Temperatures of -15 to -20 F seem necessary to kill hemlock woolly
adelgid. It might get that cold in MA, but it doesn't seem likely to get
that cold in the Smokies.
The current cold snap is being caused by the Arctic Oscillation, which has
reached the most negative reading recorded (since recording began in the
1950s). It basically is a change in air pressure that squeezes the polar
vortex in such a way that cold air bulges south in the eastern U.S. and
western Europe, while Greenland is much warmer than normal. The opposite
pattern occurs when the AO is positive.
Lee
JamesRobertSmith wrote:
Will this relatively long cold snap here in the South have an effect
on the insect pests that have been plaguing our forests during the
recent years of warm winters? Will it be enough to stunt or kill off
the populations of rampant native and introduce insect pests?
A question from an interested fan of this site: is the bulge of the polar
vortex
a part of global warming? any relationship? We did study forestry in my
geomorphology class, that got me interested in Old Growth Forests,
(geography major) and backpacking enhanced my love of trees. Jean Kinsey
