Spatial pattern and evolutionary trends of agricultural greenhouse facilities in China from 2010 to 2022

Facility agriculture, with greenhouse facilities as its cornerstone, serves as a critical driver of agricultural modernization by enhancing productivity, optimizing spatial allocation, and mitigating phenological constraints. Despite its strategic importance, systematic analyses of the spatiotemporal evolution of greenhouse facilities distributions at the national scale remain limited, hindering evidence-based policymakin. This study employs spatial autocorrelation and standard deviation ellipse methods to analyze the distribution dynamics of China’s agricultural greenhouse facilities from 2010 to 2022, to provide data support for national-level facility agriculture planning, management, and policy formulation. The results show that:1) From 2010 to 2022, China’s agricultural greenhouse facilities exhibited a new pattern characterized by "doubled total coverage, multiplied high-density clusters, western expansion, and multi-polar development". The greenhouse facilities area surged from 55 5460 hm² to 1 295 480 hm², with an increase of 133%. The number of Class V counties increased from 3 to 8, Class IV counties increased from 6 to 30, and Class III and Class II counties also increased, while the number of Class I counties without greenhouse facilities decreased from 1 620 to 985. 2) The global Moran’s I index declined from 0.27 to 0.23 during 2010 to 2022, indicating that although greenhouse facilities still show a mild clustering trend, the overall distribution was becoming more dispersed. The number of high-high clustering units initially decreased and then rebounded. There were 125 high-high clustering units in 2010 (mainly were located in Shandong and Liaoning), decreased to 105 in 2016, and increased to 127 in 2022, with the increase concentrated in Yunnan. The number of low-low clustering units continued to expand from 526 to 761, mainly were located in the central and western provinces such as Sichuan, Hunan, and Guangxi. Policy guidance, market demand, and resource endowment together drove the shift of the pattern of agricultural greenhouse facilities from “the dual-core pattern in the east” to"stable in the east, rising in the west, and multi-polar development." 3) From 2010 to 2022, China's agricultural greenhouse facilities showed an overall expansion trend, though with notable variations across different time periods. From 2010 to 2016, the dominant trend was "rapid increase" with 41.32% of counties experienced growth rates exceeding 80%, mainly distributed in Hebei and Shanxi. Only 8.06% of counties experienced rapid decreases, mainly in Yunnan and Anhui. From 2016 to 2022, due to the stricter policies, the number of counties with trend of "rapid increase" decreased, and the hotspot was shifted to Yunnan and Henan. The number of counties with trend of "rapid/moderate decrease" increased to 751, mainly in Shanxi and Guangdong, with contraction were observed in Shandong and Hebei. The spatial centroid shifted from Pingyuan County, Shandong Province, to Weihui City, Henan Province, with a movement of 177.07 km to the west and 196.96 km to the south. The long axis of the standard deviation ellipse increased by 188.21 km from 2010 to 2016 and by 130.59 km from 2016 to 2022, indicating a slowdown in the speed of expansion. Meanwhile, 99.47% of greenhouse facilities were distributed below an altitude of 2 000 meters, and 97.38% of greenhouse facilities were distributed on slopes below 4°. The proportion of greenhouse facilities in the altitude range of 1500-2000 meters had increased from 1.83% to 9.25%, and those on slopes above 4°increased from 1.68% to 3.86%, indicating that greenhouse facilities were steadily penetrating higher gradients and more complex terrains. These findings deepen the understanding of the dynamic of the spatial and temporal patterns of China’s agricultural greenhouse facilities and can provide scientific support for the planning and management decision-making.