泗水县湿地外来入侵植物分析

Alien Invasive Plants in Wetland of Sishui County

通过野外实地调查、资料查询和系统分析,对泗水县湿地外来入侵植物的种类组成、生活型、区系、原产地、繁殖及扩散方式进行了研究。结果表明:泗水县湿地有外来入侵植物39种,隶属于14科26属,其中菊科(10种)和苋科(9种)种类最多,分别占25.64%和23.08%。草本植物(38种,97.4%)尤其一、二年生草本(28种,71.8%)占绝对优势,乔木仅刺槐1种。区系地理具有泛热带性质,在科一级分为世界分布(50.00%)、泛热带分布(35.71%)和北温带分布(14.29%)3个分布区类型。在属一级分为7个分布区类型,泛热带分布(30.77%)占优势,其次为世界分布(26.92%)和北温带分布(19.23%)。起源地分析表明,原产美洲的入侵种最多(26种,40.00%),危害性也更大,列入《中国外来入侵物种名单》的12种入侵植物有11种来自美洲。绝大多数入侵植物依靠种子繁殖(35种,89.74%),营养繁殖的仅刺槐、喜旱莲子草和凤眼蓝3种,白车轴草兼具有性繁殖和营养繁殖。繁殖体能广泛借助风力、水流、动物、人类等外界媒介扩散,一些还能通过自身主动传播。

Species composition,life forms,flora,origin,reproduction and dispersal of alien invasive plants in wetland were investigated in Sishui County.According to statistics,a total of 39 alien invasive plant species was identified in this area,which falls into 26 genera and 14 families.Compositae and Amaranthaceae are two biggest groups,accounting for 25.64%and 23.08%,respectively.Herbal plants(38 species,97.4%)take up a majority of invasive species,especially annual or biennial herbs(28 species,71.8%).Robinia pseudoacacia is the only one arbor species.Floristic geography is characterized with three types at family level:Cosmopolitan,Pantropic and North temperate,accounting for 50.00%,35.71%and 14.29%respectively,while with 7 types at genus level,among which the top three were Pantropic(30.77%),Cosmopolitan(26.92%)and North temperate(19.23%).Origin analysis indicted that 26 species was originally from the Americas,accounting for 40.00%.There are 11 species were recorded in the'List of Alien Invasive Species in China'and were originally from America.Majority of the species were found to propagate through seeds,accounting for 89.74%,and only 3 species,that is,Robinia pseudoacacia,Alternanthera philoxeroides and Eichhornia crassipes were by vegetative reproduction.Trifolium repens could reproduce sexually by seeds as well as vegetative reproduction.Usually most propagules could be dispersed by means of external agents,such as wind,water,animals or humans.Some invasive species could also disperse by themselves.