Spatial and temporal evolution and greenhouse gas emissions of China's agricultural plastic greenhouses.

The rapid development of the use of agricultural plastic greenhouses in China in recent years has played an important role in the generation of economic benefits from agriculture. However, it has also led to severe negative environmental impacts. Thus, it is necessary to explore the spatial and temporal evolution of agricultural plastic greenhouses in China as well as their environmental impacts so as to obtain a deeper understanding of agricultural intensification and the sustainable development of the facility agriculture industry. To this end, this study analyzed the spatial and temporal evolution characteristics of agricultural plastic greenhouses and their greenhouse gas emissions within the 2000-2020 period based on the extraction of the spatial distribution of greenhouses in China in 2000, 2010, and 2020. Landsat imagery and statistical data combined with the random forest classification method as well as life cycle analysis, were used in this study. The results obtained showed that: (1) Within the 2000-2020 period, the area covered by agricultural plastic greenhouses in China expanded from 1594.66 to 11,838.77 km, with most of the greenhouses predominantly distributed in the North China Plain. (2) The increase in total greenhouse gas emissions between 2000 and 2010 was mainly due to the expansion of agricultural plastic greenhouse and an increase in agricultural material inputs, whereas the increase between 2010 and 2020 was mainly due to the expansion of agricultural plastic greenhouse. (3) Greenhouse gas emissions from nitrogenous fertilizers and greenhouse construction materials accounted for 45 % and 36 % of the total greenhouse gas emissions, respectively. These findings are of great significance as they enhance understanding regarding land intensification development and its accompanying environmental impacts in China.