The Straight Dope

Go Back   Straight Dope Message Board > Main > General Questions

Thread Tools Display Modes
Old 04-30-2003, 07:50 AM
welby welby is offline
Join Date: Jan 2000
Why don't evergreens freeze?

My son asked me this, and instead of making up a good answer that he would beleive (he caught me off guard) I decided to admit I don't know and ask here.

In the winter, trees drop leaves for a number of reason, chief among them to avoid freezeing during very cold weather. However, evergreen trees don't do this. Why, then, don't the trees or pine needles freeze and kill the tree?
Master of Parody TM

Reply With Quote
Old 04-30-2003, 08:51 AM
Ca3799 Ca3799 is offline
Join Date: Feb 2003
The sap of some conifers has an antifreeze like substance in it. Also the gas exchange is conducted throught the very long 'leaves' (as opposed to flat leaves) which retains the trees moisture. A conifer in a very cold climate is living in conditions that can be considered desert-like in regards to available water.
Reply With Quote
Old 04-30-2003, 10:51 AM
belladonna belladonna is offline
Join Date: Feb 2001
During the winter photosynthesis stops in firs and spruces of the high forests. The water in the ground is frozen, and sometimes the water inside tree cells freezes! The trees combat the severe threat of freezing and winter water loss by developing tough cell walls, antifreeze-like sap, and a waxy coating on the needles. The tough cell wall prevents splitting when ice crystals form inside the cells; the waxy coating reduces water loss by evaporation. Cessation of photosynthesis also retards water loss. In the winter the fir trees are alive and green, but not growing.
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 04:44 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2015, vBulletin Solutions, Inc.

Send questions for Cecil Adams to:

Send comments about this website to:

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Publishers - interested in subscribing to the Straight Dope?
Write to:

Copyright 2015 Sun-Times Media, LLC.