深圳市建成区入侵植物特点及其对植物多样性的影响

Characteristics of urban invasive plants and their effects on plant diversity in the built-up area of Shen-zhen,China

城市是多数外来植物的主要分布区,也是很多入侵植物开始入侵过程的重要起点。城市入侵植物种类构成及其对植物多样性的影响作为城市生态系统的重要问题引发越来越多的关注。本研究以深圳市为例,对建成区600个城市植物样地(100 m×100 m)进行实地调查,并分析入侵植物种类构成及其对植物多样性的影响。调查共记录到入侵植物55科153属214种,生活型以草本植物为主;乔木植物银合欢(Leucaena leucocephala),灌木植物马缨丹(Lantana camara)、光荚含羞草(Mimosa sepiaria)和草本植物鬼针草(Bidens pilosa)、南美蟛蜞菊(Wedelia trilobata)以及微甘菊(Mikania micrantha)是主要的严重入侵物种;不同入侵等级的草本植物样方中,其Simpson优势度指数、Shannon多样性指数、Margalef丰富度指数以及Pielou均匀度指数均表现为重度入侵<中度入侵<轻度入侵。本文揭示城市入侵植物轻度入侵对草本植物多样性的显著影响,以及入侵程度不断增加后草本植物多样性逐渐降低的显著规律。相关结果及方法为城市入侵植物研究、城市外来植物入侵的防范提供一定的参考。

Cities are the primary distribution areas of most invasive plant species and the important starting point of invasion for many invasive plant species.As one of the important issues in urban ecosystems,the composition of urban invasive plant species and their impacts on plant diversity have received increasing attention.With the built-up area of Shenzhen as a case study,we analyzed the species composition of urban invasive plants and their impact on plant diversity using data from 600 urban plant plots(100 m×100 m).A total of 214 invasive plant species in 55 families and i53 genera were investigated,with herbaceous plants as the leading life type.Tree species Leucaena leucocephala,shrub species Lantana camara and Mimosa bimucronata,and herb species Mimosa bimucronata,Mimosa bimucronata,and Mikania micrantha were the most widespread invasive species.For herb quadrats with different invasive levels,Simpson dominance index,Shannon diversity index,Margalef richness index,and Pielou evenness index all exhibited the same order as severe invasion<moderate invasion<mild invasion.This study revealed the significant effect of mild invasion on urban herb diversity and the evident pattern of herb diversity decreasing trend with increasing invasion level.Our results and methods provide a reference for studying urban invasive plants and preventing urban alien plant invasions.