You have to give some credit to Biosphere 2 for being the most ambitious, most advanced project in the field. But it was also embarrassingly hobbyist.
They brought in way too much soil, so soil respiration consumed too much of their oxygen. And they didn't know the basic chemistry of building materials. Soils respired in oxygen and released it as CO2, and the CO2 went into the concrete walls of the buildings, as the buildings were new and the concrete was still curing.
As a result, they knew they kept losing oxygen, but because there was no corresponding rise in the air CO2 concentration, they didn't know where their oxygen was disappearing.
They brought in farm animals, and quickly found out they can't support them. They brought in too little plants, and later found out they need to start growing fast growing, easy to grow plants on almost all available soil areas, in an attempt to produce more oxygen.
It's a bit difficult to say, were these elementary mistakes because they didn't have understanding of the mass flows in the biogeochemical cycles in their ecosystem. Or was this pioneering scientific work, because nobody had such understanding at a time, and they were just in the process of finding out.
In 1970s, Russians did smaller and shorter experiments, with 1 to 3 man crews. They started by calculating, how much Chlorella algae and/or how much wheat you need to grow in order to produce enough oxygen for the people. They didn't have an expensive patchwork of copies of different types of ecosystems. They just had closed room with algae growing in tanks, and a small wheat field in a room under artificial lights.
They brought in way too much soil, so soil respiration consumed too much of their oxygen. And they didn't know the basic chemistry of building materials. Soils respired in oxygen and released it as CO2, and the CO2 went into the concrete walls of the buildings, as the buildings were new and the concrete was still curing.
As a result, they knew they kept losing oxygen, but because there was no corresponding rise in the air CO2 concentration, they didn't know where their oxygen was disappearing.
They brought in farm animals, and quickly found out they can't support them. They brought in too little plants, and later found out they need to start growing fast growing, easy to grow plants on almost all available soil areas, in an attempt to produce more oxygen.
It's a bit difficult to say, were these elementary mistakes because they didn't have understanding of the mass flows in the biogeochemical cycles in their ecosystem. Or was this pioneering scientific work, because nobody had such understanding at a time, and they were just in the process of finding out.
In 1970s, Russians did smaller and shorter experiments, with 1 to 3 man crews. They started by calculating, how much Chlorella algae and/or how much wheat you need to grow in order to produce enough oxygen for the people. They didn't have an expensive patchwork of copies of different types of ecosystems. They just had closed room with algae growing in tanks, and a small wheat field in a room under artificial lights.
https://en.wikipedia.org/wiki/BIOS-3