关键词: Sphaerophysa salsula, 系统发育, 16S rDNA PCR-RFLP, 16S rDNA全序列, 遗传多样性

AbstractIn order to examine the effects of the invasive plant Spartina alterniflora on insect diversity in Jiuduansha wetlands in the Yangtze River Estuary, we surveyed insects in monoculture stands of three species by net-sweeping and plant-harvesting methods from May 2004 to October 2005. A total of 11,300 insects were collected, belonging to 12 orders, 69 families and 97 species. We found that species number and Shan-non-Wiener index of the insect community in Spartina alterniflora monoculture were significantly lower than those in the two native monocultures (Phragmites australis and Scirpus mariqueter). However, Simp-son’s dominance index was higher in Spartina alterniflora monoculture. Cluster analysis indicated that, for both survey methods, the similarity of insect communities between Phragmites australis and Scirpus mari-queter was higher than that between Spartina alterniflora and the two native communities. We conclude that invasions of Spartina alterniflora might lead to reduction of insect diversity and alteration of insect commu-nity structure in Jiuduansha wetlands.