外来入侵植物黄顶菊在我国的地理分布格局及其时空动态

【目的】黄顶菊是20世纪90年代入侵我国的恶性外来杂草,近年来呈快速扩散蔓延趋势。全面解析黄顶菊在我国的扩散动态对制定早期监测预警等管理措施具有重要意义。【方法】通过查阅文献和标本记录及实地调查等途径重建了黄顶菊在我国扩散的历史过程,分析了其地理分布格局及其主要扩散路线,以及最早入侵地与传入途径。【结果】黄顶菊最早入侵河北省南部的邯郸、衡水,其后主要沿公路扩散蔓延,71%的分布点在距入侵地国道等主要公路2 km的范围内。目前,该杂草已从最初的入侵地向北扩散到天津市,向东扩散到山东省东营市,向西扩散到了山西省黎城市,向南扩散到了河南省开封市。黄顶菊向4个方向扩散的直线距离不等(100～350 km),这种差异与自然屏障和扩散通道相关。太行山脉是黄顶菊向西扩散的地理屏障,但这个屏障已逐渐被突破。至今,黄顶菊已入侵华北地区5个省市(河北、山东、天津、河南和山西)的100余个县。【结论】黄顶菊在我国仍处于快速扩散阶段,未来应该会继续沿公路向南和向西蔓延。因此,亟需在扩散的前沿地带开展监测预警工作,以抑制其在我国的进一步扩散。

The geographic distribution pattern and spatiotemporal dynamic of the invasive alien plant Flaveria bidentis (Asteraceae) in China

Aim] Flaveria bidentis (L.) Kuntze is one of the notorious alien plants that has rapidly spread in China since 1990s. It is necessary to elucidate the spatial-temporal invasion and expansion processes in China to prevent or mitigate its further invasion.Method] We reconstructed its invasion and expansion process by collecting information from herbarium records, literature, and field investigations. Its invasion vectors and expansion routes were examined by analyzing the temporal changes in its geographic pattern.Result] F. bidentis firstly invaded Handan and Hengshui City in the southern part of Hebei Province. It then spread to neighboring regions along roads with 71% of the earliest occurrence points being within 2 km of major roads. It has now spread 350 km north to Tianjin City, 350 km east in Dongying City in Shandong Province, 250 km to the south in Kaifeng City in Henan Province, and 100 km to the west in Licheng City in Shanxi Province. The heterogeneity of the speed of spread of F. bidentis in different directions in China might be related to natural barriers and expansion route. The Taihang Mountains should be geographical barriers to prevent its spread to the west. F. bidentis however could break through this barrier along the roads with the human activities. By 2017, F. bidentis had invaded over 100 counties of five provinces in northern China.Conclusion] F. bidentis is still in a stage of rapid expansion. It might continue to spread southwards and westwards from the invaded areas in the future. It is imperative to establish early monitoring at the forefront of expansion to curb its spread.