新疆千里光Senecio jacobaea在中国的适生区预测

Prediction of the potential distribution of Senecio jacobaea in China

【背景】菊科植物新疆千里光原产于欧亚大陆,在北美和澳洲为入侵植物,目前在中国只有新疆有分布记录。新疆千里光一旦成为入侵植物,将对农业、畜牧业和人类健康都可能产生危害,所以需要评估其在中国的扩散趋势。【方法】搜集新疆千里光在中国和世界其他地区的分布记录,结合当前和未来(2050年)气候条件下19种生物气候变量,应用Maxent模型和Diva Gis软件,定量预测新疆千里光在中国目前和未来的潜在分布区域;并通过接受者操作特征曲线(ROC)分析法对模型进行精度检验。另外,通过Maxent给出新疆千里光在欧洲(原产地)、北美洲和大洋洲(入侵地)以及中国等4个分布区的年均温度和年均降水量的气候阈值。【结果】用中国和全球分布的数据预测的结果有些差异。前者结果表明除了新疆地区,其他省份几乎没有新疆千里光的适生区;而后者显示在中国其他几个省份也有可能分布,且在甘肃四川交界处有较高适生性。前者模型精确度较高,但2个结果都显示新疆千里光在中国目前和未来的分布区大部分还是在新疆地区。中国分布区年均温度和年均降水量的阈值比其他2个地区都低。【结论与意义】新疆千里光在当前和未来气候条件下在中国未来的扩散趋势较弱,基本局限于新疆地区。用中国分布数据预测优于全球分布数据预测结果,新疆千里光不同分布区的气候阈值的差异揭示分布于中国的新疆千里光与其他地区的种群的生态位有所不同,可能是一个新的亚种,希望未来能进行进一步的研究。

[ Background] Senecio jacobaea, a common weed native in Eurasia and invasive in North American, Australia and New Zealand. However, the occurrence records of this species in Xinjiang, China, are limited. Once successfully introducted, S. jaco- baea can be damaging to crop, livestock farming, and human health. Hence, it is urgent to estimate the potential distribution of S. jacobaea in China. [ Method] Based on 19 current and predicted （2050） climate variables and occurrence records from China and the other areas in the world, we quantitatively predicted the current and future potential distribution of S. jacobaea in China with the Maxent and DivaGIS. The predicted models were evaluated by the receiver operator characteristic （ ROC ） curve. In addition, we cal- culated the climate thresholds of annual mean temperature and annual precipitation of the S. jacobaea distribution in different areas （Europe -- the native area, North America and Oceania -- the invasive area, and China） by modeling in Maxent. [ Result] The model built with occurrence data from China is better than that with the data from the whole world in relation to ROC curve and com- parison to the occurrence record from China, but results of both model show that the current and future distribution area of S. jaco- baea is in Xinjiang, China. The annual average temperature and precipitation in China are lower than in other regions for S. Jacobaea invasion. [ Conclusion and significance] S. jacobaea is and will be limited in Xinjiang China. The differences between two predicting models and different climatic thresholds of S. jacobaea distribution in China compared to that in other regions indicate that the popu- lations of S. jacobaea in Xinjiang differ from those in other regions and may be a different subspecies.