南宁市园林绿地系统外来入侵植物物种调查与分析

Analysis of Alien Invasive Plants Species in the Landscape Green Space System of Nanning City

为了解南宁市园林绿地外来入侵植物物种及其分布状况,抽取该市园林绿地系统34个绿地单元,调查其外来入侵植物。结果表明,南宁市园林绿地外来入侵植物种类繁多,共有116种,隶属于32科88属,其中以菊科物种最多,达24属31种,分别占属数和种数的27.27%、26.72%;其次为豆科和禾本科,分别有8属12种和8属9种,种数各位居第2和第3。南宁市园林绿地系统出现频率较高的入侵植物有11种,隶属于5科9属,这些外来物种入侵了30多个绿地单元,鬼针草(Bidens pilosa)、红花酢浆草(Oxalis corymbosa)、藿香蓟(Ageratum conyzoides)等为广布种,几乎在每个绿地单元均可见其踪影,表明此类植物极易在南宁市定殖,占据生态位并排挤本地植物。按生活型统计,南宁市园林绿地外来入侵植物以草本植物占绝对优势,共有96种,占入侵植物种数的82.76%;其中一年生、二年生草本植物有56种,占48.28%;多年生草本植物有33种,占28.45%;草质藤本植物有7种,占6.03%;木本植物种类较少,共有20种,占17.24%。南宁市园林绿地系统外来入侵植物原产于美洲、非洲、亚洲(除中国外)、欧洲和大洋洲。其中原产于美洲的物种最多,有89种,占76.72%;其次原产于非洲的有10种,占8.62%;原产于大洋洲的最少,仅有2种,占1.72%。

The presence and distribution of alien invasive plants was determined in 34 landscape green space units in Nanning City.There were 116 alien species belonging to 32 families and 88 genera.Twenty seven percent of the plants(24 genera and 31 species)belonged to Compositae.Both Leguminosae and Poaceae were represented by eight genera and 12 and nine species,respectively.Eleven species belonging to 5 families and 9 genera were highly frequent,invading at least 30 green space units.Among them,Bidens pilosa,Oxalis corymbosa,and Ageratum conyzoides were found in almost every green space,indicating their ability to colonize and occupy ecological niches in detriment of the local flora.The great majority of invasive plants(96 species representing 83%of those found)were herbs,56(48%)of them were annual or biennial herbs and 33 species(28%)were perennial.There were also seven species(6%)of herbaceous vines and 20 species(17%)of xylophyta.Alien invasive plants of Nanning City originated mostly from America(89 species),but some arrived from Africa,Asia(except China),Europe and Oceania.