广州市主要河流中22座未开发江心岛上的入侵植物种类及其分布特征

Species and Distribution Characteristics of Invasive Plants on 22 Undeveloped Islands in Major Rivers of Guangzhou City

分布于流溪河等河流中未开发的江心岛具有生态和文化等多重价值,这些未开发的江心岛是广州市碧道建设实施方案中的重点保护对象。外来入侵植物是江心岛生态系统健康发育的潜在危害因素。为了全面掌握广州市主要河流中未经市政开发的江心岛上的入侵植物分布状况,通过现场调查和查阅相关文献资料,研究了广州市珠江水系中22座未开发的江心岛上的入侵植物种类和分布特征。研究结果表明,在22座未开发的江心岛上,共记录11科26属27种入侵植物,这些物种都为广州市已经记录的入侵植物物种,其中,菊科(Compositae)物种(10种)最多;白花鬼针草(Bidens pilosa)在11座江心岛上分布,光荚含羞草(Mimosa bimucronata)在10座江心岛上分布,薇甘菊(Mikania micrantha)、马缨丹(Lantana camara)和南美蟛蜞菊(Sphagneticola trilobata)的分布也较广;东江流域的泊鹤洲上的入侵植物物种(11种)最多,其次为南航道的屎船沙(10种);白花鬼针草、南美蟛蜞菊、薇甘菊、光荚含羞草、五爪金龙(Ipomoea cairica)和原野菟丝子(Cuscuta campestris)已经在所分布的江心岛上形成单优势物种群落,并且对江心岛上的乔木和灌木产生了危害,这6种入侵物种被划定为恶性入侵物种,建议在江心岛生态保护中优先清除这些物种;人类的农业开发活动和农田撂荒等是导致外来植物入侵江心岛的主要原因。

The undeveloped islands distributed in the rivers including the Liuxi River have multiple ecological and cultural values.These undeveloped islands are important protection subjects considered by the greenway construction projects.The invasive plants have become a potential hazard affecting the healthy development of the island ecosystem.In order to fully understand the distribution of invasive plants on the undeveloped islands in rivers of Guangzhou,this study analyzed the species and distribution characteristics of invasive plants on 22 undeveloped islands in Guangzhou Pearl River system through on-site investigation and literature review.The results showed that,on these 22 islands,27 species of invasive plants belonging to 11 families and 26 genera were identified,all of which had been recorded as invasive plants in Guangzhou.Among them,the species of Compositae(10 species)were the most abundant species.Moreover,Bidens pilosa and Mimosa bimucronata distributed in 11 islands and 10 islands.Meanwhile,Mikania micrantha,Lantana camara,and Sphagneticola trilobata also distributed widely.The most abundant invasive plant species(11 species)were found on the Baihe island in the East River Delta,followed by the Shichuansha island in the Southern Channel(10 species).Bidens pilosa,Sphagneticola trilobata,Mikania micrantha,Mimosa bimucronata,Ipomoea cairica,and Cuscuta campestris have formed single dominant species communities and exhibited invasive hazards on the arbor and shrub on the distributed islands.Since these 6 species were classified as vicious invasive species,it is suggested to primarily remove these species during the ecological protection of the islands.Human activities such as agricultural reclamation and farmland abandonment were important factors causing these species to invade the islands.