From: Russell Blackford (rblackford@hotmail.com)
Date: Thu Feb 06 2003 - 16:35:33 MST
Oh, and thanks for this too. I think I now have enough thoughts to go on
from you and Anders. It's nice to have people to bounce this off.
R
http://www.users.bigpond.com/russellblackford/
>From: "Robert J. Bradbury" <bradbury@aeiveos.com>
>Reply-To: extropians@extropy.org
>To: extropians@extropy.org
>Subject: Re: PERIPHERAL - bio/ecological query
>Date: Thu, 6 Feb 2003 09:39:42 -0800 (PST)
>
>
>On Thu, 6 Feb 2003, Russell Blackford wrote:
>
> > Okay, imagine a fairly full-on nuclear exchange causes a dark nuclear
>winter
> > of several months' duration. Imagine further that the global climate
> > thereafter tips over into something like ice-age temperatures. [snip]
> >
> > IF it happened like this, what would the major tropical/equatorial
>forests
> > of places like Brazil look like after, say, 15-30 years? Presumably they
> > would die but a lot of the big trees would remain standing. What sort of
>new
> > vegetation could we expect to grow in what waa left of these jungles?
>
>It really depends on how dark it gets for how long. The Sagan lengthy
>nuclear winter hypothesis has been fairly disproven I believe.
>
>First, many of the below canopy plants stand a good chance of surviving.
>They are adapted to very low light conditions -- unless the "winter"
>created *really* extended, totally dark conditions, some sunlight would
>still make it through the clouds/fog. Then you have to consider rain
>forest plants -- these spend much of their time under a lack of direct
>sun (in Seattle this is 7-8 months a year even not being in a rain
>forest). Finally, if the temperatures drop there are many plants
>from tundra and high altitude environments that will just migrate
>southward and to lower altitudes respectively.
>
>It might also depend what time of the year the nuclear exchange
>took place. Many plants, particularly in temperate zones store
>a lot of their resources in their roots during the winter.
>Provided some sunlight returns by the spring they are likely
>to recover fairly well. Equatorial forests do not do this
>but the under-canopy growth should stand a fighting chance.
>A better question might be how the "endarkenment" might
>impact rainfall. Less sunlight means less evaporation means
>less rain (even though the small atmospheric particles might
>be better at seeding increased rainfall). The plants are
>likely to suffer more from a lack of water (which drives
>photosynthesis) than a lack of sunlight.
>
>Robert
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