03-03-2003, 05:15 PM
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Messinian climate
In article ,
(Jaak Suurpere) writes:
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| It follows that many plants now growing in Azizija, or their
| ancestors, have heated to 58 degrees and lived. Actually, sunlight
| ground and plants on it could heat to higher temperatures than air in
| shadow!
They do, as I can witness. Thermophilic bacteria can take much
higher temperatures, too.
| It would seem likely that plants which can endure 58 degrees and low
| humidity could also endure 58 degrees and high humidity.
Not so. Inter alia, high humidity permits fungi to flourish. Few
USA plants would last a month in the humid tropics, and none from
outside the deep south would. But there would be plants that could
adapt, given long enough.
| Now, the area with currently the highest dewpoint temperatures -
| southern Red Sea region - does not really have that great absolute
| temperature maxima. What makes the heat troublesome for men - not
| intolerable, since they do live there, and long have - is the fact
| that there are consistent high temperatures with high humidity.
Fairly high. Not very high. Nowhere near the tropical jungles.
| Now try to imagine a region where night temperatures are in lower 40-s
| and day temperatures in upper 40-s, with high humidity. Occasional
| maxima might be somewhere in 50-s, with high humidity...
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| Men would not endure. On the other hand, many plants might.
It is unclear, given enough water. I don't know whether mammals'
requirements are for a bound on the relative humidity dependent
on temperature, or for a margin in water vapour pressure between
ambient and maximal (i.e. dew point).
If the latter, mammals would survive. And we are fairly typical
in this respect.
| Not all the plants, though. I wonder which plants would choose to grow
| in such conditions?
Nothing current, but some of them could adapt.
| One more thing: these conditions might be unfavourable to many
| animals, including herbivores.
Yes, they would be.
Regards,
Nick Maclaren,
University of Cambridge Computing Service,
New Museums Site, Pembroke Street, Cambridge CB2 3QH, England.
Email:
Tel.: +44 1223 334761 Fax: +44 1223 334679
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