重庆市主城建成区主要绿地的植物种类构成研究

Study on the composition of plant species in the built-up area of Chongqing main area

采用分层随机抽样法调查了重庆市主城建成区道路、居住区、单位、公园四类主要绿地共132个,从植物科属、来源、生活型、区系、优势种、多样性、入侵种七个方面分析了绿地植物种类构成,并采用双向指示种分类(TWINSPAN)分析植物群落。结果表明:(1)本次调查共记录维管束植物135科376属550种,生活型以草本植物为主,物种多样性指数以居住区绿地最高而公园绿地最低;(2)外来植物占42%,其中81%是引种的观赏植物,外来植物区系以热带成分为主;(3)乔灌植物优势种均为栽培植物,草本80%优势种和90%主要群丛指示种为自生植物,自生草本植物利用潜力巨大。(4)26种入侵植物中80%是草本植物,且在四类绿地中分布均匀,红花酢浆草(Oxalis corymbosa)、垂序商陆(Phytolacca americana)、喜旱莲子草(Alternanthera philoxeroides)、小蓬草(Conyza canadensis)四种危害较大的入侵植物已成为绿地主要群丛的指示种;(5)TWINSPAN分类得到乔灌和草本植物主要群丛类型及其物种多样性。研究结果为城市绿地植物种类选择提供参考。

The Stratified Random Selection was used to investigate 132 patches of green space in the built-up area of Chongqing main urban area,including street green space,residential green space,institutional green space,and park green space.The species composition was analyzed in seven aspects,including species families,species origin,life forms,chorological spectra,dominant species,species diversity,and invasive plants,and the Two-Way Indicator Species Classification(TWINSPAN)was used to classify and analyze the plant communities.The results showed that:(1)The investigation recorded 550 species from 376 genera and 132 families of vascular plants.Herb was the dominant life form.The species diversity index was the highest in residential areas and the lowest in parks.(2)Alien plants accounted for 42% of species,of which 81% were introduced ornamental plants.Tropical components dominated the chorological spectra of alien plants.(3)The dominant species of trees and shrubs were all cultivated plants,80% of dominant herb species and 90% of the main community indicator species were spontaneous plants,so the potential for the use of spontaneous herbs was vast.(4)80% of the 26 invasive plants were herbs which were evenly distributed among the four types of green space.Four harmful invasive plants,including Oxalis corymbosa,Phytolacca americana,Alternanthera philoxeroides and Conyza canadensis,became indicators of the main community in green space.(5)The TWINSPAN classification results revealed the main community types and species diversity for trees,shrubs and herbs.Results from this research provide a reference for the plant species selection in urban green space.