Objective This paper aims to understand the geographical distribution and potential distribution area of Paeonia jishanensis in China, so as to conduct research on resource protection, introduction and domestication of P. jishanensis and garden application.
Method Using ArcGIS software and MaxEnt model, based on 44 current effective distribution records of P. jishanensis and 17 environmental variables, this paper assesses the influence of different environmental factors on the geographical distribution of P. jishanensis, and predicts its current and future potential distribution area.
Result MaxEnt model simulated the current potential distribution area with high accuracy, and the AUC values of training set and test set were 0.994 and 0.998, respectively. Lowest monthly average of radiation (UVB4, contribution rate of 21.6%), annual precipitation (BIO12, contribution rate of 18.8%), lowest temperature of the coldest month (BIO6, contribution rate of 12.3%), altitude (ALT, contribution rate of 10.5%) were the main influencing factors affecting the current distribution of P. jishanensis. The total area of contemporary ecologically suitable areas was 15.97 × 104 km2, which was mainly located in eastern Gansu and central Shaanxi of northwestern China, southern Shanxi of northern China, and northwestern Henan of central China. In addition, there was also a small amount of distribution at the junction of southern Hebei and Shanxi provinces of northern China. Under the future climate change, the potential distribution area of P. jishanensis will shrink in the northwest and expand slightly to the east and north. The specific performance is that it will shrink significantly in the east of Gansu, Baoji City and Xianyang City of Shaanxi, and completely lose in the south of Hebei. It will expand slightly in the north of Yan’an in Shaanxi, Linfen in Shanxi, Jincheng in Henan and Luoyang in Henan. In addition, its suitable distribution center will move eastward in the future.There are also a small number of areas at the junction of southern Hebei and Shanxi. Under future climate change, the potential suitable areas for P. jishanensis will shrink in the northwest and slightly expand to the east and north. The specific manifestation is that the areas of Longdong, Baoji and Xianyang in Shaanxi have been significantly reduced, and the southern Hebei area will be completely lost. In the north of Yan’an in Shaanxi, Linfen and Jincheng in Shanxi, and the east of Luoyang in Henan slightly expanded. In addition, the future suitable distribution center of P. jishanensis is moving eastward obviously.
Conclusion The suitable area for P. jishanensis is mainly affected by four environmental conditions: the lowest monthly average radiation (819.4−1 128.6 J/(m2∙d)), the average annual precipitation (436.2−808.5 mm), the lowest temperature of the coldest month (−11.8− −3.2 ℃) and the altitude (270.8−1 833.3 m), the lowest monthly average radiation and annual precipitation are identified as the most critical environmental factors restricting the distribution of P. jishanensis. At present, its geographical distribution is relatively narrow in China. In the future, suitable habitats in the northwestern China and southern Hebei will be drastically reduced. Thus, it is urgent to strengthen the protection of natural populations and actively carry out introduction and cultivation.