Objective To predict the potential suitable habitats of Andrographis paniculata in China, clarify the impact of climate change on its distribution dynamics, and provide a scientific theoretical basis for the artificial introduction, standardized cultivation, industrial layout optimization, and sustainable development and utilization of A. paniculata medicinal resources, while addressing the challenges posed by the changing distribution patterns of medicinal plant resources under the background of global warming.

Method Geographical distribution data of A. paniculata in China were obtained through databases including the Global Biodiversity Information Facility (GBIF), Chinese Virtual Herbarium and literature retrieval. After eliminating duplicate, abnormal, and high-coordinate-error points using the ENMtools tool, 89 valid distribution points were retained; a total of 50 initial environmental factors were selected, covering climate (e.g., annual mean temperature, mean temperature of the wettest quarter), topography (elevation, slope), soil (pH, total potassium), and distance to water bodies, through correlation analysis and contribution rate screening of the MaxEnt model, 12 key environmental factors were finally determined; the ENMeval package in R was used to optimize the model parameters, and the optimal combination was identified as RM=2.5 and FC=L+Q, and further based on the optimized MaxEnt model and combined with ArcGIS spatial analysis technology, the potential suitable habitats of A. paniculata under four different time periods (1970—2000, 2021—2040, 2041—2060, and 2061—2080) climate scenarios (SSP245: medium-low emission; SSP585: high emission) were simulated, and divided into four grades: highly suitable area, moderately suitable area, lowly suitable area, and non-suitable area;

Result The dominant environmental factors affecting the distribution of A. paniculata were annual mean temperature (contribution rate 45.5%), distance to water bodies (contribution rate 42.8%), mean temperature of the wettest quarter (contribution rate 3.5%), and temperature seasonality (contribution rate 1.1%). Under past climatic conditions, the total area of potential suitable habitats of A. paniculata was 255.10×10⁴ km² (accounting for 26.59% of China's land area), among which the highly suitable area was 31.60×10⁴ km² (3.29%), concentrated in South China (central-southern Guangdong, central-southern Guangxi, southern Fujian, coastal Taiwan, and the whole of Hainan) and southern Yunnan, the moderately suitable area was 52.21×10⁴ km² (5.44%), extending to northern Guangdong, northern Guangxi, southern Hunan, southeastern Guizhou, southern Jiangxi, and southeastern Sichuan, and the lowly suitable area was 171.28×10⁴ km² (17.86%), covering most of Hunan, most of Jiangxi, Jiangsu, Zhejiang, Anhui and other regions. Under future climate scenarios, the total area of suitable habitats showed an expanding trend, with the total suitable area presenting "fluctuating expansion" under the SSP245 scenario and more significant expansion under the SSP585 scenario; under both scenarios, the highly suitable area still took South China as the core, the moderately suitable area extended to East China and Central China, and the centroid of suitable habitats was always located within the scope of Guizhou and Chongqing (past centroid: Chongqing, 29.775°N, 107.558° E), showing an overall migration trend of "first to low latitudes, then to high latitudes".

Conclusion Climate change can significantly promote the expansion of suitable habitats of A. paniculata, and the expansion effect is more prominent under the high-emission scenario. The research results can provide an important basis for the protection of germplasm resources in the core suitable areas of A. paniculata, introduction planning in potential areas, optimization of cultivation techniques, and sustainable industrial development.