基于SSPs气候场景的濒危植物银杉潜在分布区预测

Prediction of potential distribution areas of the endangered Cathaya argyrophylla based on shared socio-economic pathways(SSPs)climate scenarios

【目的】探讨影响濒危植物银杉(Cathaya argyrophylla)种群发生的关键因子及预测其在当前与未来的潜在分布区,为银杉天然种质资源的保护和引种栽培提供理论依据。【方法】基于银杉的41个样本点,结合气候、地形、土壤、辐射因子数据,采用MaxEnt模型预测当前情景下银杉的潜在分布区,评估不同环境因子对银杉地理分布的影响,同时以未来共享社会经济数据(SSPs)作为气候数据,预测银杉未来的潜在分布区。【结果】当前气候条件下,银杉核心适生区面积约为1.325×10^(5)km^(2),约占我国国土面积的1.38%;最干月份降水量、下行紫外线辐射、海拔、最冷月份最低温度对银杉分布影响的累计贡献率为91.9%,是影响银杉地理分布的主导因子。未来3种气候情景下,银杉核心适生区面积均有增加,但仍以黔、湘、桂、渝为中心。【结果】当前气候条件下,银杉核心适生区面积约为1.325×10^(5)km^(2),约占我国国土面积的1.38%,最干月份降水量、下行紫外线辐射、海拔、最冷月份最低温度对银杉分布影响的累计贡献率为91.9%,是影响银杉地理分布的主导因子。未来3种气候情景下,银杉核心适生区面积均有增加,但仍以黔、湘、桂、渝为中心。以生存概率大于0.5作为适应范围,则适宜银杉生存的主要环境条件为:最干月份降水量18.03~215.63 mm,下行紫外线辐射1070728~1437806 W/m^(2),海拔493.68~1731.10 m,最冷月最低温-1.01~4.05℃。【结论】最干月份降水量、下行紫外线辐射可以被认定是影响银杉潜在分布的主要因子。在3种未来气候情景下,银杉的核心适生区均呈扩张趋势,扩张区主要分布于云南、浙江、福建、贵州4省。此外,中间发展路径情景(SSP2-4.5)更适合银杉的生长与繁殖。

[Objective]This study explored key factors affecting the occurrence of endangered Cathaya argyrophylla populations and predicted their potential distribution areas in the present and future,providing a theoretical basis for the conservation and introduction of C.argyrophylla natural resources.[Method]Based on 41 sample sites of C.argyrophylla,the MaxEnt model was used to predict the potential distribution areas of C.argyrophylla under the current scenario by combining climate,topography,soil and radiation factor data,and to assess the effects of different environmental factors on the geographical distribution of C.argyrophylla.Also,future shared socio-economic pathways(SSPs)were used as climate data to predict future changes in the growth distribution areas of C.argyrophylla.[Result]Under the current climate conditions,the core suitable area for C.argyrophylla is approximately 1.325×10^(5)km,accounting for approximately 1.38%of China's land area.It has a cumulative contribution rate of 91.9%to the distribution of C.argyrophylla due to precipitation in the driest month,downward ultraviolet radiation,altitude,and the lowest temperature in the coldest month.They are the dominant factor affecting the geographical distribution of C.argyrophyla.If the survival probability is greater than O.5 as the adaptation range,the main environmental conditions suitable for the survival of C.argyrophylla are:precipitation in the driest month is 18.03~215.63 mm,downward ultraviolet radiation is 1070728~1437806 W/m^(2),altitude is 493.68~1731.10 m,and the lowest temperature in the coldest month is-1.01~4.05℃.In the future,under SSP1-2.6,SSP2-4.5,and SSP5-8.5,the core suitable areas for C.argyrophylla will increase.However,they will still be centered in Guizhou,Hunan,Guangxi,and Chongqing.[Conclusion]Precipitation during the driest month and downward ultraviolet radiation were the main factors influencing the potential distribution of C.argyrophylla.Under the three future climate scenarios,the core area suitable for C.argyrophylla showed an expanding trend.The expansion areas were mainly distributed in Yunnan,Zhejiang,Fujian and Guizhou.The intermediate development scenario(SSP2-4.5)was more suitable for the growth and reproduction of C.argyrophylla.This study provides an important theoretical basis for the conservation of C.argyrophylla planting resources.