PDA

View Full Version : plants in looong nights



Barabino
2015-Feb-18, 12:53 PM
Concerning slow-rotation greenhoused terrestrial exoplanets -- like a colder Venus...

I used to think that long nights would just kill vegetable life (vegetables can't store lipids in their body), but...

http://en.wikipedia.org/wiki/Polar_forests_of_the_Cretaceous

Temperate polar-night forests have undoubtedly existed... and have left fossils of big trees! :clap:

grapes
2015-Feb-18, 01:12 PM
Concerning slow-rotation greenhoused terrestrial planet like Venus...

I used to think that long nights would just kill vegetable life (vegetables can't store lipids in their body), but...

http://en.wikipedia.org/wiki/Polar_forests_of_the_Cretaceous

Temperate forest undoubtedly existed... and left fossils of big trees! :clap:
Weird. That wiki says "The duration of summer sunlight and winter darkness lasted for approximately 5 months each."

But it references an article that says something different. The forests didn't grow where there was five months of continuous dark.

Squink
2015-Feb-18, 06:21 PM
Current northenmost forest is at about 72.5 (http://en.wikipedia.org/wiki/List_of_northernmost_items#Plants). Looks like darkness lasts about a month and a half up there (fig. 6i-2 (http://www.physicalgeography.net/fundamentals/6i.html)).

Barabino
2015-Feb-19, 05:43 PM
But now the circumpolar zone is not only dark, but also freezed... that kills plants too!

Noclevername
2015-Feb-19, 10:23 PM
But now the circumpolar zone is not only dark, but also freezed... that kills plants too!

And largely under seawater or glacial ice.

Trebuchet
2015-Feb-20, 12:15 AM
Evolution. Life evolves (or not) to suit its environment. OUR plants don't store lipids. Those that evolve elsewhere might store them. Or do something else entirely.

Noclevername
2015-Feb-20, 12:34 AM
OUR plants don't store lipids.

http://en.wikipedia.org/wiki/Lipid


Triglycerides, stored in adipose tissue, are a major form of energy storage both in animals and plants.

http://en.wikipedia.org/wiki/Triglyceride


Triglycerides are the main constituents of vegetable oil

Trebuchet
2015-Feb-20, 02:41 AM
http://en.wikipedia.org/wiki/Lipid

http://en.wikipedia.org/wiki/Triglyceride

Indeed. I almost went back and edited when I realized plants store lots of lipids in their seeds but hadn't got around to it.

Seeds, of course, are a good way for plants to overwinter, even if the parent generation has died off. Lots of plants do just that.