Subject: water plants winter

From: [email-masked] (SLURF)
Date: 29 Apr 1996 22:00:22 GMT

What do plants that live in water do during winter months? 

                                                             Thanks a million,
                                                               Jessie

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From: [email-masked] (Brian the Great)
Date: Tue, 30 Apr 1996 06:54:04 GMT

>                                                               Jessie

They freeze.

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From: Tony Travis <[email-masked]>
Date: Sat, 04 May 1996 14:04:35 +0000

> >What do plants that live in water do during winter months?

The maximum density of water occurs at 4 oC which is why ice forms at 
the surface (normally, cold water is more dense than warm water and 
sinks, but between 0-4 oC the colder water is less dense and rises).

That means that unless the lake or pond freezez completely there will 
still be liquid water below the ice surface. This is how some fish and 
other aquatic animals survive the winter. Once formed, the layer of ice 
insulates the water beneath from futher cooling to an increasing extent 
as it thickens, which slows down the rate of ice formation.

Aquatic plants could survive in this water without freezing. However, a 
more serious problem is the low light levels and short days during the 
winter which limits photosynthesis. Terrestrial plants have evolved may 
ways of surviving the winter in a dormant state to avoid this problem.

Have aquatic plants evolved similar strategies?

	Tony.
--
Dr. A.J.Travis,                     |  mailto:[email-masked]
Rowett Research Institute,          |    http://www.rri.sari.ac.uk/~ajt
Greenburn Road, Bucksburn,          |   phone:+44 (0)1224 712751
Aberdeen AB2 9SB, Scotland, UK.     |     fax:+44 (0)1224 716687

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From: [email-masked] (Charles Hesselein)
Date: Thu, 9 May 1996 13:24:54 GMT

In <[email-masked]> Tony Travis <[email-masked]> writes:

There are several tactics that aquatic plants use to survive the winter.  
Many aquatic plants have storage structures (e.g., tubers, rhizomes, 
bulbs) which help them survive adverse conditions such as drought or 
freeze.  Some plants may produce seeds which are generally tolerant of 
adverse conditions.  Also see this months National Geographic which gives 
an example of algae which thrives in antarctic ice.  Ice is translucent 
so it is possible that some species of plants could survive and be active 
beneath the ice.

Chazz 
>Brian the Great wrote: >> >> [email-masked] (SLURF) wrote: >> 

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