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小叶栎(Quercus chenii)是华东植物区系的代表树种,具有很高的生态、经济价值。为重建冰期以来小叶栎地理分布格局的变迁历史、了解环境因子对潜在地理分布的制约机制,为小叶栎种质资源保护和管理提供科学依据,该研究基于55条分布记录和8个环境变量,利用Max Ent模型模拟小叶栎在末次盛冰期、全新世中期、现代和2070年(温室气体排放情景为典型浓度目标8.5)的潜在分布区,利用多元环境相似度面和最不相似变量分析探讨气候变迁过程中环境异常区域和引起潜在地理分布改变的关键因素,综合应用贡献率及置换重要值比较、Jackknife检验评估制约现代地理分布的主要因子,采用响应曲线确定环境变量的适宜区间。研究结果表明:Max Ent模型的预测准确度极高,受试者工作特征曲线下的面积(AUC值)达0.986 9±0.004 5;现代高度适宜区在安徽南部、浙江西部、江西东北部和湖北东部;影响小叶栎地理分布的主要气候因子为气温和降水量,气温更重要;最干季平均气温可能是制约小叶栎向北分布的关键因素;末次盛冰期时,小叶栎高度适宜区位于东海大陆架内;全新世中期适宜分布区轮廓已与现代近似;2070年适宜分布区向北移,高度适宜区面积增大,与末次盛冰期、全新世中期和现代相比,这一时期的气候异常程度最高。气温季节变化和降水季节变化可能是引起地理分布变迁的重要气候因素。
Quercus chenii is a representative tree species in East China and has high ecological and economic value. To understand the history of the change of geographical distribution pattern of Quercus variabilis since the ice age, understand the restriction mechanism of environmental factors to the potential geographical distribution and provide a scientific basis for the conservation and management of Quercus liaotungensis. Based on 55 distribution records and 8 environmental variables, The Max Ent model was used to simulate the potential distribution of Quercus variabilis in the last ice age, mid-Holocene, modern and 2070 (greenhouse gas emission target is typical concentration target 8.5), and the multivariate environmental similarity and the least-common variable were used to analyze the climate In the process of change, the key factors that cause the change of the potential geographical distribution are the key factors of the change of the potential geographical distribution. The Jackknife test is used to evaluate the main factors restricting the modern geographical distribution and the response curve is used to determine the appropriate range of environmental variables. The results show that the prediction accuracy of Max Ent model is very high, and the area under the working curve of subjects (AUC) is 0.986 9 ± 0.004 5. The modern highly suitable area is located in southern Anhui, western Zhejiang, northeastern Jiangxi and Hubei Eastern China. The main climatic factors influencing the geographical distribution of Quercus mongolica are air temperature and precipitation, and the temperature is more important. The average temperature in the driest season may be the key factor restricting the distribution of Quercus variabilis to the north. At the last ice age, Quercus liaotungensis is located in the East China Sea In the mid-Holocene, the profile of the suitable distribution area has been similar to the modern one. The suitable distribution area moved northward in 2070 and the area of high suitable area increased. Compared with the mid-Holocene, mid-Holocene and modern times, the climate anomaly The highest degree Seasonal changes in air temperature and seasonal variations in precipitation may be important climatic factors that cause changes in geographical distribution.