Ecological Assessment of Oxygen Balance: A Case Study of China’s Natural Oxygen Bars

Ecological assessment plays a vital role in sustainable development of the environment, and thus exploration of specific and integrated ecological assessment methods has become a critical task. In this study, based on the concept of oxygen balance and by accommodating both natural factors and socioeconomic elements, we establish an oxygen (O₂) balance index (OBI), i.e., the ratio of the O₂ production from the ecosystem to the O₂ consumption by human behavior, based on the net primary productivity (NPP), fuel consumption, gross domestic production (GDP), population data, and so on. The results show that the spatial distributions of OBI in China are intimately correlated to the regional vegetation and socioeconomic development. The estimated OBI values are then validated by statistical data from 27 counties in China, and it is found that the OBI reflects the ecological environment status well. Moreover, the average OBI values derived from 190 natural oxygen bars in China reveal extreme imbalance between O₂ production and consumption in highly developed regions, especially in the cities, in contrast to good O₂ balance in areas with high-quality ecological status and less industrialization. The findings from this study have quantitatively captured the regional ecological quality, providing guidance for sustainable natural and socioeconomic developments in local areas of China.