> Biosphere 2 fell apart

Wait, what's this? What happened?

Biosphere2 was an experiment to seal humans and plants i to a dome and not open it for some time.

Fungus and other pests destroyed some important plants and the eco system collapsed.

It had been built in the middle of a desert but urban expansion means the site is reasonably near housing now.

There were a bunch of photos of the dusty derelict interiors floating around a few years ago.

I kind of wish people would try again, just becuase.

I thought the biggest problem was the concrete. That is, soil microbes produced excess CO2, which would have been okay because the plants should have been able to photosynthesize it to O2, but instead the excess carbon dioxide reacted with the concrete, thus reducing the O2 levels.

Ah, here's a summary of the various things that went wrong, including details about the concrete: http://biology.kenyon.edu/slonc/bio3/2000projects/carroll_d_... .

It doesn't mention fungus, but does talk about other ecosystem problems (the pollinating insects died out, the morning glories took over, etc.).

Evidently it's not derelict anymore... the University of Arizon has owned it since 2011. Lookin' pretty cool!

https://en.wikipedia.org/wiki/Biosphere_2

If you're ever in Tucson, you should go for a tour. It's a fascinating place, and they've repurposed the facility to do a lot of worthwhile and interesting science.

I can't see how decaying plant matter would provide enough CO2 to keep the larger greenery healthy. Perhaps the original soil had an exceptional amount, but it would take time for it to break down; plants can empty a container such as that of CO2 in a day or so.

Isn't it how the world worked before animals evolved? Or is there some yet another source of CO2?

Fungus produces CO2 from plant tissues as well, so they are probably an important component of this ecosystem.

Did you just imply Fungi are plants?

Huh... no, what would make you think that?