Distribution patterns of Platycodon grandiflorus from the last inter-glacial period to the future by ecological niche modeling

Global climate change may represent a significant threat to the distribution and quality of medicinal plants, altering cultivation areas and compromising the quality of medical materials. Platycodon grandiflorus, a traditional Chinese medicinal herb, has a millennia-long medicinal and culinary use history in East Asia. Given its escalating demand, accurately evaluating the changes under different climate scenarios and predicting its potential distribution are imperative for ensuring its conservation and sustainable utilization. By integrating MaxEnt with ArcGIS, this study advances previous approaches by incorporating historical, present, and future climate data to model the distribution dynamics of P. grandiflorus acrossChina. The results indicated: (1) The species' distribution strongly correlates with environmental variables, particularly bio13, prec07, prec09 and tmin07, whose cumulative value of percent contribution was 78.5%; (2) The centroids of potential geographic distribution during the LIG, LGM, and MH periods were situated further westward compared tothe present distribution, with substantial contraction observed in highly suitable habitats throughout these historical periods; (3) Under present climatic conditions, the overall suitable habitat encompasses4,185,964 km2, withhighly suitable habitats constitutingone-third of this expanse, predominantlyconcentrated in central, southern, and northeasternChina; (4) Future climate change scenarios predict that the total suitable habitat will expand to varying degrees (7% increase on average), albeit with potential reductions in highly suitable areas (3% decrease on average); (5) The distribution of P. grandiflorus is likely to move towards higher latitudes in the future due to climate changes. Our findings fill a critical knowledge gap by quantifying the impact of climate change on the distribution of P. grandiflorus. These resultsoffer crucialinsights for developing effective conservation strategies, promoting sustainable utilization, and establishing standardized cultivation protocols for P. grandiflorus resources.