Element cycling and energy flux responses in ecosystem simulations conducted at the Chinese Lunar Palace-1

Bioregenerative life-support systems (BLSS) address interactions between organisms and their environment as an integrated system through the study of factors that regulate the pools and fluxes of materials and energy through ecological systems. As a simple model, using BLSS is very important in the investigation of element cycling and energy flux for sustainable development on Earth. A 105-day experiment with a high degree of closure was carried out in this system from February to May, 2014, with three volunteers. The results indicate that 247 g·d^-1 carbon was imported into the system from stored food. Most hydrogen is circulated as water, and more than 99% H₂O can be lost through leaf transpiration into the atmosphere. A total of 1.8 g·d^-1 "unknown oxygen" emerged between the input and output of the plant growth module. For the urine processing module, 20.5% nitrogen was reused and 5.35 g·d^-1 was put into the nutrient solution.