ABSTRACT
Objective:To analyze the main factors affecting the <italic>Ziziphus jujuba</italic> distribution and expand the understanding of its distribution and the corresponding influencing factors by comparing the distribution sites of <italic>Z. jujuba</italic> predicted by models with those recorded in the literature. Method:More than 200 distribution sites of <italic>Z. jujuba</italic> accompanied by 55 environmental factors were obtained from literature and specimen review. The environmental factors that affect the distribution of <italic>Z. jujuba</italic> were explored by maximum entropy （MaxEnt） model， and the potential distribution areas of <italic>Z. jujuba</italic> in China were analyzed by ArcGIS， followed by the verification of the main environmental factors using receiver-operating characteristic （ROC） curve and Jackknife method. Result:The area under the curve （AUC） values for the test data and training data were both greater than 0.9， which perfectly satisfied the standard， indicating that the research results were accurate and reliable. Conclusion:The annual average temperature， the average temperature in May， the average temperature in the warmest season， vegetation type， soil type， average temperature in June， average temperature in September， and average temperature in August are proved to be the main environmental factors affecting the distribution of <italic>Z. jujuba</italic>， which can be found almost all over China， except for Heilongjiang and Tibet. <italic>Z. jujuba</italic> is most suitable to be planted in southeastern Sichuan， Chongqing， southern Gansu， Ningxia， most areas of central Shaanxi， eastern and southwestern Shanxi， Henan， eastern and northern Hubei， northern and eastern Anhui， Shandong， Hebei， Beijing， Tianjin， western Liaoning， and Zhejiang. As revealed by literature review， the most suitable growing areas of <italic>Z. jujuba</italic> are southeastern Sichuan， central Shaanxi， southwestern Shanxi， western and northern Henan， Shandong， and southwestern and eastern Hebei.
ABSTRACT
Objective:To explore the potential suitable distribution area and the high-quality distribution area of <italic>Sabia parviflora</italic>. Method:Combined with the distribution information and environmental factors，the maximum entropy （MaxEnt） model and ArcGIS software were used to predict the potential suitable distribution area of <italic>S. parviflora</italic>. Based on the correlation between environmental factors and total saponins，total flavonoids，quercetin-3-<italic>O</italic>-gentiobioside，camellianoside，tsubakioside A，kaempferol-3-<italic>O</italic>-rutinoside and isobariclisin-3-<italic>O</italic>-rutinoside，the quality regionalization was conducted by using spatial interpolation method and fuzzy superposition function in ArcGIS software. Result:<italic>S. parviflora</italic> is mainly distributed in Yunnan，Guizhou，Guangxi province in China. The medium and high suitable areas accounts for about 2.88% of the national area. The precipitation in October and November，the precipitation in the warmest and driest seasons，the standard deviation of seasonal changes in temperature and altitude are the main environmental factors that affect the distribution of <italic>S. parviflora</italic>. Slope，precipitation，solar radiation and temperature change had great influence on the accumulation of secondary metabolites. Based on the results of potential suitable distribution and spatial interpolation of each component，the high-quality areas of <italic>S. parviflora</italic> are mainly concentrated in the southwest of Guizhou，with Qinglong，Guanling，Zhenning，Pu'an，Xingren county and other areas as the core. Conclusion:This study provides a scientific guidance for the site selection of artificial planting and the procurement of medicinal materials for <italic>S. parviflora</italic>.