重要外来入侵植物随南水北调工程传入京津冀受水区的风险评估

【目的】外来物种在入侵地的扩张蔓延是其造成危害的关键。南水北调工程可为已入侵外来物种的进一步扩张蔓延提供通道和驱动力。风险评估可为预防入侵植物通过该途径的扩散蔓延提供依据。【方法】以国家重点管理外来入侵物种名录中的入侵植物为研究对象,根据生物入侵的发生过程(传入、定殖、扩散、危害)构建了包括4个层次29个指标的外来物种入侵综合风险评估的指标体系,规范了风险指数的计算方法,系统评估了24种入侵植物沿南水北调输水通道向北扩散而入侵京津冀受水区的风险。【结果】紫茎泽兰和互花米草的入侵风险值(R)相对较低(R0.6),其余22种入侵植物的风险值均较高(R0.6),其中,喜旱莲子草、凤眼莲和大薸3种外来水生植物的入侵风险等级最高(R0.8)。【结论】南水北调工程可能会促进入侵植物向北扩张蔓延并最终入侵京津冀受水区。建议尽早开展监测预警工作,以控制入侵物种随南水北调工程的扩张蔓延,进而阻止或降低其对京津冀尤其是华北最大水源地——白洋淀和雄安新区生态环境的威胁。

Invasion risk assessment of major invasive alien plant species in the South-to-North Water Division project in Beijing-Tianjin-Hebei region

[Aim] The range expansion of alien species causing ecological problems in newly invaded regions is of great concern for managers. The South-to-North Water Division project can provide new channels leading to the spread of invasive species.[Method] The study analyzed the potential of invasion of plants found in the shortlist of alien invasive species under national key management. An index was developed for comprehensive risk assessment of invasive alien species. The systematic risk assessment of 24 invasive plants spreading northward along the South-to-North Water transfer channel in the Beijing-Tianjin-Hebei region was carried out.[Result] Except for Ageratina adenophora and Spartina alterniflora with relatively low value of risk (R<0.6), the risk values of the remaining 22 invasive plants are all high (R>0.6), among which three invasive aquatic plants, Alternanthera philoxeroides, Eichhornia crassipes and Pistia stratiotes, have the highest risk levels (R>0.8).[Conclusion] The project may promote the spread of invasive plants to the north and eventually invade the Beijing-Tianjin-Hebei water receiving area. It is recommended that early monitoring and warning measures should be taken to prevent and control the spread of invasive species along with the project.