湖南省靖州县外来入侵植物研究

Research on alien invasive plants in Jingzhou County,Hunan Province,China

外来入侵植物的危害程度在湖南省靖州县正日益加深。本研究通过为期一年的野外调查,结合相关文献资料,对靖州县外来入侵植物的物种组成、原产地、区系、危害程度与分布格局进行了研究。结果表明:靖州县共有外来入侵植物16科27属34种,其物种主要以菊科和苋科为主,分别为8种(23.5%)和6种(17.7%);外来入侵植物的原产地以南美洲(45.7%)和北美洲(30.4%)为主。外来入侵植物的热带科属区系成分显著高于温带科属区系成分,表现出强烈的热带区系性质。根据危害等级将外来入侵植物划分为恶意入侵类(1级)4种(喜旱莲子草、一年蓬、小蓬草和北美苍耳)、严重入侵类(2级)5种,局部入侵类(3级)8种、一般入侵类(4级)15种、有待观察类(5级)2种。靖州县外来入侵植物主要分布在各级交通道路两侧、人类居住地和部分水流区域,入侵危害程度较重的区域主要集中在靖州县中部。

Harm from alien invasive plants is increasing in Jingzhou County,Hunan Province.Based on a one-year field investigation and available literature,we investigated species composition,origin,flora,degree of harm and distribution pattern of invasive plants in the county.The results showed that there were 34 invasive plant species from 27 genera and 16 families in this County.The dominant invasive species belonged to Asteraceae(8 species)and Amaranthaceae(6 species),which accounted for 23.5%and 17.7%,respectively.The majority of invasive plants originated from South America(45.7%)and North America(30.4%).Tropical flora showed a significantly higher representation than temperate flora,signifying robust tropical characteristics amongst the invasive plant population.Based on hazard level classification,we recognized four types as malicious invasion(Level 1):Alternanthera philoxeroides,Erigeron annuus,E.canadensis,and Xanthium chinense.In addition,five types were classified as severe invasion(Level 2),eight types as local invasion(Level 3),fifteen types as general invasion(Level 4),while two types were still under observation(Level 5).The pattern of distribution demonstrated that invasive plants in Jingzhou County mostly spread along the verges of transportation roads,in human settlements,and in a few areas of water flow.The higher levels of invasion damage were principally concentrated in the central part of Jingzhou County.