不同气候情景下黄心梓木在我国的潜在适生区预测

Prediction of Potential Distribution for Huangxin(Catalpa)in China under Different Climate Scenarios

【目的】预测不同气候情景下黄心梓木在我国的分布情况及其自然群体可能的迁移路线,为黄心梓木的保护和可持续利用提供科学依据,为濒危植物的潜在适生区预测和保护提供参考。【方法】基于当前和未来(2030s、2050s、2070s)4个时期的环境变量数据以及黄心梓木分布数据,利用MaxEnt模型模拟预测不同气候情景下黄心梓木在我国的潜在地理分布,综合分析限制其扩散的环境因子,制定针对性保护措施。【结果】1)MaxEnt模型各组曲线下面积(AUC)均高于0.9,模型预测结果非常准确。2)黄心梓木在我国的潜在适生区狭窄,当前适生区总面积为50416 km^(2),其中高适生区面积2309 km^(2),仅在黔南和黔西南部分地区分布,中适生区(面积14288 km^(2))在其周围分布,低适生区面积33819 km^(2),分布在贵州中部、广西、云南、四川等地;未来气候情景下,黄心梓木在我国的潜在适生区呈先扩张后收缩的变化趋势,其中高强迫(SSP5-8.5)情景下的2030s时期适生区总面积最大(70313 km^(2)),新增面积达当前适生区总面积的39%。3)最干月降水量(bio14)、海拔(bio20)、等温性(bio3)、年降水量(bio12)是限制黄心梓木分布的主导环境因子。4)未来气候情景下,黄心梓木潜在适生区的质心迁移方向总体为先向北移后向东南移。5)基于黄心梓木现状提出在高适生区范围内就地划分保护区,在湖北西部、重庆东北部等潜在适生区开展相关育种试验扩大其种植面积以及建立种质资源库等相关保护措施。【结论】黄心梓木在我国的潜在适生区较为狭窄且中、高适生区相对集中,大多分布在贵州西南部,广西、云南、四川、重庆以及湖北部分地区也可能有分布;目前黄心梓木的潜在适生区未达到饱和,预计适生区面积会持续扩增至2030s;未来气候情景下,黄心梓木潜在适生区面积呈先扩大后缩小的趋势;基于黄心梓木现状,建议以人为方式开展协助恢复其生境以及快速促进其种群扩大等相关保护措施。

【Objective】This study intends to predict the suitable habitat of Huangxin under different environmental scenarios in current and future periods based on the MaxEnt model.The aim is to explore the distribution of Huangxin,provide a scientific basis for the protection and sustainable use of Huangxin and also serves as a reference for the prediction and protection of potential suitable habitats for endangered plants.【Method】This study,based on the MaxEnt model and incorporating environmental variable data from the present and future periods(2030s,2050s,2070s),simulated and predicted the potential geographic distribution of Huangxin under different climate scenarios.Through a comprehensive analysis of the environmental factors limiting its spread,we have formulated targeted conservation measures.【Result】1)The area under the curve(AUC)values of all groups in the MaxEnt model were higher than 0.9,indicating high accurate model predictions.2)Huangxin has a narrow potential suitable area in China,with a total current suitable area of 50416 km^(2).The high suitable area is only 2309 km^(2),located in parts of southern and southwestern Guizhou Province.The medium suitable area(14288 km^(2))is distributed around the high suitable area.The low suitable area,amounting to 33819 km^(2),is distributed in central Guizhou Province,Guangxi Zhuang Autonomous Region,Yunnan Province and Sichuan Province.Under future climate conditions,the potential suitable area for Huangxin shows a trend of first expanding and then contracting over the three periods.Among them,the total suitable area could reach its maximum(70313 km^(2))in the 2030s under the high forcing(SSP5-8.5)scenario,with an increase of 39%compared to the current total suitable area.3)The precipitation of the driest month(bio14),altitude(bio20),isothermality(bio3),and annual precipitation(bio12)are the dominant environmental factors limiting the distribution of Huangxin.4)Under future climate scenarios,the potential suitable area for Huangxin shows a trend of first expanding and then contracting,with a migration direction first northward and then southeastward.5)Based on the current situation of Huangxin,we propose relevant conservation measures:delineating protected areas in situ within the high suitable range;conducting relevant breeding experiments in potential suitable areas such as western Hubei Province and northeastern Chongqing Municipality to expand its planting area;and establishing a germplasm resource bank.【Conclusion】The suitable habitat for Huangxin is relatively narrow,with the medium to high suitable areas predominantly concentrated in southwestern Guizhou Province.Low suitable areas may also be distributed in parts of Guangxi Zhuang Autonomous Region,Yunnan Province,Sichuan Province,Chongqing Municipality,and Hubei Province besides Guizhou Province.The current suitable area for Huangxin has not reached saturation,and it is projected to reach its maximum area in the2030s.Under future climate scenarios,the area of potential suitable habitats is expected to first expand and then contract.Given the current status of Huangxin,it is recommended to carry out human-assisted measures such as habitat restoration and rapid promotion of population recovery.