苏州地区外来入侵植物组成及分布

为了解苏州外来入侵植物的种类组成及分布概况,对苏州地区6个县市(包括常熟、昆山、苏州、太仓、吴江和张家港)26个样点内不同生境中的外来入侵植物进行了调查分析.调查结果显示:每个样点有外来人侵植物7～25种,平均每个样点有17.9种.在26个样点中观察到外来入侵植物57种,隶属于19科45属；其中菊科(Compositae)种类最多(23种),占总种数的40.4％；豆科(Leguminosae)、玄参科(Scrophulariaceae)、禾本科(Poaceae)、伞形科(Apiaceae)、苋科(Amaranthaceae)和旋花科(Convolvulaceae)种类也较多.原产于北美洲和欧洲的种类分别有20和12种,分别占总种数的35.1％和21.0％；还有17种原产于美洲的其他区域,少数种类原产于非洲、西亚和地中海地区.在57种外来入侵植物中,草本植物有55种,非多年生植物有44种,分别占总种数的96.5％和77.2％.有18种的频度超过50％,其中加拿大一枝黄花(Solidago canadensis L.)和一年蓬Erigeron annuus (L.) Pers.]的频度最高,分别达到96.15％和92.31％,且多度等级均属于极多级(Soc)；空心莲子草 Ahernanthera philoxeroides( Mart.) Griseb.]和白车轴草(Trifolium repens L.)的频度也均在80％以上,且多度等级也属于极多级(Soc).调查结果表明:苏州地区外来植物入侵现象比较严重.

Composition and distribution of invasive alien plants in Suzhou area

In order to understand species composition and distribution of invasive alien plants in Suzhou,invasive alien plants in different habitats of 26 sample plots in six counties or cities(including Changshu,Kunshan,Suzhou,Taicang,Wujiang and Zhangjiagang) of Suzhou area were investigated and analyzed.The investigation results show that there are 7-25 species of invasive alien plants in these plots with the average of 17.9 species per plot.There are 57 species of invasive alien plants observed in 26 sample plots,belonging to 45 genera in 19 families.In which,species number in Compositae(23 species) is the most,which accounts for 40.4% of total species number.And species number in Leguminosae,Scrophulariaceae,Poaceae,Apiaceae,Amaranthaceae and Convolvulaceae is also more.Number of species originated from North America and Europe is 20 and 12 with the percentage of 35.1% and 21.0% of total species number,respectively,there are 17 species originated from other regions of America and a few species originated from Africa,West Asia and Mediterranean.In 57 species of invasive alien plants,there are 55 herb species and 44 non-perennial plants accounting for 96.5% and 77.2% of total species number,respectively.There are 18 species with the frequency over 50%,in which,frequency of Solidago canadensis L.and Erigeron annuus(L.) Pers.is the highest with the value of 96.15% and 92.31%,respectively,and their abundances belong sociales scale(Soc).And also,frequency of Alternanthera philoxeroides(Mart.) Griseb.and Trifolium repens L.is over 80% with an abundance of sociales scale(Soc).It is concluded that the invasive phenomenon of alien plants in Suzhou area is very serious.