The authors used Biosphere-2 as a reference point for their study. The experiment was carried out in the 1990s in Arizona (USA) with the aim of creating a self-sustaining ecosystem completely cut off from the rest of the world. After two attempts, the scientists had to abandon the experiment. The topic, however, has never lost its appeal; but typically, closed ecological systems are associated with space travel and life support systems for astronauts. One of the goals of the paper, according to Matthias Rillig, is to disentangle the study of these closed systems from this particular context. The biologists want to establish microbial biospherics as its own ecological discipline, in which microbial ecosystems can be used to expand our knowledge of closed biospheres.

Rillig and Antonovics hope to spark new ideas in not only ecological and evolutionary research, but also teaching. Rillig notes that first semester biology students are usually sent out to study ecosystems, like grasslands or rivers, which are extremely complex systems. But it would be better for them to observe simple ecosystems and material cycles, especially early on in their studies, he says. Ultimately, closed ecological systems can also provide insights into how circular economies work.