矮牡丹在中国的地理分布及潜在分布区预测

Geographical distribution and potential distribution area prediction of Paeonia jishanensis in China

【目的】了解矮牡丹在中国的地理分布和潜在的适生区,以进行矮牡丹的资源保护、引种驯化及园林应用研究。【方法】利用ArcGIS软件和MaxEnt模型,基于矮牡丹当前44条有效分布记录和17个环境因子,评估不同环境因子对矮牡丹地理分布的影响,预测其当前及未来的潜在适生区。【结果】MaxEnt模型模拟当前潜在分布区的结果准确度极高,训练集与测试集的AUC值分别为0.994和0.998。紫外线最低月平均值(UVB4,贡献率为21.6%)、年均降雨量(BIO12,贡献率为18.8%)、最冷月最低温(BIO6,贡献率为12.3%)和海拔(ALT,贡献率为10.5%)为影响当前矮牡丹分布的主要环境因子。当前生态适生区总面积为15.97万km^(2),主要位于甘肃东部、陕西中部、山西南部及河南西北部地区,此外,河北南部与山西两省交界地带也有少量分布。未来气候变化下,矮牡丹潜在分布区有西北部缩减和向东部、北部轻微扩张的趋势,具体表现为:在陇东地区、陕西宝鸡市、咸阳市一带出现明显缩减,冀南地区则完全丧失,在陕西延安以北、山西临汾、晋城、河南洛阳以东轻微扩张。此外,其未来的适宜分布中心东移趋势明显。【结论】矮牡丹适生区主要受紫外线最低月平均值(819.4~1128.6 J/(m2∙d))、年均降水量(436.2~808.5 mm)、最冷月最低温(−11.8~−3.2℃)、海拔高度(270.8~1833.3 m)等环境条件影响,其中紫外线最低月平均值与年均降水量是限制矮牡丹地理分布最关键的环境因子。当前,矮牡丹在中国地理分布范围较窄,未来在西北、冀南地区适宜生境骤减。因此,加强天然种群保护力度,积极开展引种栽培工作刻不容缓。

[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 km^(2),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(819.4−1128.6 J/(m^(2)∙d)),the average annual precipitation(436.2−808.5 mm),the lowest temperature of the coldest month(−11.8−−3.2℃)and the altitude(270.8−1833.3 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.