气候变化背景下糙果紫堇在中国适宜分布区的预测

Prediction of Suitable Distribution Area of Corydalis trachycarpa(Papaveraceae)in China under Climate Change

为探究糙果紫堇(Corydalis trachycarpa)的潜在适宜分布区,明确其适宜的生存环境,旨在为糙果紫堇的资源利用和保护提供一定的理论依据。基于糙果紫堇现有的分布位点、气候变量和环境变量数据,利用MaxEnt模型和ArcGIS软件模拟糙果紫堇当前气候条件下(1970—2000年)和未来SSP 245情境模式下4个时期(2021—2040年、2041—2060年、2061—2080年、2081—2100年)在我国的潜在分布区,分析限制其分布的环境因子。结果表明(:1)影响糙果紫堇分布的最主要环境变量分别是海拔(Alt,贡献率60.9%)、温度季节性变化标准差(bio4,贡献率11.1%)、最暖季度降水量(bio18,贡献率9.4%)、降水量变异系数(bio15,贡献率7.0%),这4个变量的累计贡献率高达88.4%;(2)当前气候条件下,MaxEnt模型预测糙果紫堇的潜在分布区总面积约174.94万km^(2),主要分布在青藏高原东部的四川西北部、甘肃南部、西藏东部、云南西北部和青海等地;(3)与当前气候条件下相比,SSP 245情境下未来4个时期糙果紫堇高、中、低适生区面积均有所增加,呈现向云南、西藏东部等低纬度地区扩张的趋势。

In order to explore the potential suitable distribution area and the suitable living environment of Corydalis trachycarpa,and to provide a theoretical basis for resource utilization and protection of C.trachycarpa.Based on the existing distribution sites,climatic variables,and environmental variables of C.trachycarpa,MaxEnt modeling and ArcGIS software were used to simulate the potential distribution of C.trachycarpa in China for four periods under current climate condition(1970-2000)and Shared Socioeconomic Pathway(SSP)245 scenario model(2021-2040,2041-2060,2061-2080,2081-2100),and environmental factors limiting its distribution were analyzed.The results showed that the most important environmental factors determining C.trachycarpa distribution were altitude(Alt,contribution rate was 60.9%),standard deviation of temperature seasonality(bio4,contribution rate was 11.1%),precipitation during the warmest quarter(bio18,contribution rate was 9.4%),and the precipitation variation coefficien(t bio15,contribution rate was 7.0%).The cumulative contribution of these four factors was 88.4%.Under current climate conditions,the MaxEnt model predicted a total potential distribution area of approximately 1.7494×10^(6) km^(2)for C.trachycarpa,primarily distributed in northwest Sichuan,southern Gansu,eastern Xizang,northwest Yunnan,and Qinghai within the eastern Tibetan Plateau.Compared with the current climate conditions the most,moderate and low suitable areas of C.trachycarpa under SSP 245 scenario might increase in the next four periods,showing a trend of expansion toward Yunnan,eastern Xizang,and other lower latitude regions.