Do we know how long does it take for life to bounce back to previous levels after an ice age ? By previous levels I mean the total living biomass on earth.
Also - does the polar ice trap atmospheric bacteria with it ? Also, is the concentration of bacteria in a core sample a good measure of the total biomass on earth at time the ice was packed ?
First we would need to establish that net biomass is reduced in an Ice Age. Arctic seas are among the most productive biomes.
I totally thought this thread was going to be about isostatic rebound! The thread title suits that subject perfectly.
Carry on. (Assuming we’ll restrict ourselves to purely terrestrial biota – but there are other factors besides retreating ice sheets and warming temperatures. Precipitation, mainly. Does the post-glacial region become warm and wet, or warm and dry?).
If by “ice age”, you mean the glaciation/inter-glaciation cycles the Earth has been experiencing, then I’d guess very little. As DrFidelius noted, the marine biota wouldn’t be affected very much, and terrestrial biota would fill in where the ice once was. Though not a small area, compared to all the biota it wouldn’t really amount to much increase … and it would be quickly doomed to death.
However, if you mean a return to mid-Cretaceous climate, then I think life would flourish in all it’s forms, tropical rainforests pole to pole. This would be an immediate response, life on Earth has a habit of filling any ecological niche rather quickly.
This might interest you;
The Vegetation History of Snowdonia since the Late Glacial Period
Wales, and England in general, took a little longer to ‘bounce back’ due to its isolated location; but there were oak forests by 8660 BP, indicating that the ecology had almost completely recovered, about one and a half thousand years after the end of glaciation.
All matters of life bounce back pretty quickly.
When I was in my early teens there was a rather large landslide the next town over due to heavy rains. I drove by that place for all my teen and college years many times looking at that scar on the hillside.
Now you drive that same road you can not tell at all that landslide even occurred. It is totally forested over. That is a period of time of 40 years.
A related question occurs to me.
In the ice ages much land was lost covered by Ice. However much land was also gained as the sea level dropped many hundreds of feet. Was there a net gain of land mass or a net loss?
I suspect it was about the same and the new landmass from the drop in the sea levels became forested and wild life settled in there very quickly.