摘要
【目的】揭示互花米草Spartina alterniflora入侵对盐沼湿地昆虫不同功能群组成特征和时间动态的影响。【方法】于2015年的不同季节,在不同的样点沿10 m长的样线,以扫网法对长江口九段沙湿地不同样点的互花米草、芦苇和藨草群落进行昆虫采集。采用非参数检验方法比较不同植物群落中不同昆虫取食功能群物种丰富度、个体多度和季节动态的差异,采用非参数多维度排序方法分析植物生境对各昆虫功能群组成的影响,并用指示种分析方法分析不同昆虫的生境偏好。【结果】共采集昆虫72科,188种,10 338头。互花米草群落昆虫物种丰富度和个体多度显著低于芦苇群落,藨草群落昆虫物种丰富度与互花米草群落差异不显著,但昆虫个体数显著多于互花米草群落。不同昆虫功能群分别比较表明,植食昆虫物种数和个体数在互花米草和芦苇群落间差异不显著,藨草群落植食昆虫物种数最少但个体数量最多。芦苇群落捕食/寄生昆虫物种数和个体数均显著多于互花米草和藨草群落。腐食/菌食昆虫物种数和个体数在不同植物群落无显著差异。季节动态分析显示,不同昆虫功能群物种数和个体数在互花米草群落的峰值均出现在春季,而在芦苇和藨草群落中则具不同趋势。根据非参数多维度排序分析结果,互花米草入侵显著改变了昆虫的群落结构,并对不同昆虫功能群的物种组成均产生了显著影响。指示种分析方法结果进一步表明,偏好互花米草的昆虫物种数最少,主要为广食性植食昆虫。偏好芦苇分布的昆虫物种数最多,主要为捕食/寄生昆虫和专食性植食昆虫。偏好藨草的植食昆虫虽为广食性,但指示值较高。【结论】互花米草入侵降低了盐沼湿地的昆虫多样性,并显著改变了盐沼湿地昆虫功能群组成特征和季节动态。相比植食昆虫,天敌昆虫对互花米草入侵的影响更为敏感。一些广食性的植食昆虫可能已对互花米草产生了适应机制,其可能造成的生态学后果应引起重视。
【Aim】This study aims to explore the effects of Spartina alterniflora invasion on the structural characteristics and seasonal dynamics of insect functional groups in salt marshes. 【Methods】In 2015,insects were seasonally collected by a sweeping net along a 10 m long transect line in different sample plots of S. alterniflora,Phragmites australis and Scirpus triqueter communities in Jiuduansha wetland of theYangtze River Estuary,East China. The nonparametric test method was adopted to compare the variations in the species richness,individual abundance and seasonal dynamics of different functional feeding groups of insects between different plant communities. The effects of plant habitats on the assemblage compositions of different insect functional groups were assessed by the nonmetric multidimensional scaling( NMS) ordination analysis. The habitat preferences of insect species were analysed by the indicator species analysis( ISA). 【Results】A total of 10 338 individuals belonging to 188 species in 72 insect families were collected. Species richness and individual abundance of insects were significantly lower in S. alterniflora than in P. australis. The species richness of insects in Sc. triqueter was not significantly different from that in S. alterniflora. However,the individual number of insects in Sc. triqueter was significantly higher than that in S. alterniflora. As far as different insect functional groups were concerned,Sc. triqueter had the lowest species number but the highest individual number of insect herbivores. Both species and individual numbers of insect herbivores were not significantly different between S. alterniflora and P. australis. The species richness and abundance of predator / parasitoid insects were significantly higher in P. australis than in S. alterniflora and Sc. triqueter. The species and individual numbers of insect detritivores were not significantly different among plants. In addition,it was shown that the richness and abundance of all insect functional groups in S. alterniflora reached their peak values in spring. However,in P. australis and Sc. triqueter,different functional groups reached their species richness and abundance peaks in different seasons. According to the results of NMS ordination analysis,S. alterniflora invasion significantly changed the insect community composition,even when each functional group was individually concerned. According to the results of ISA,the number of insect species preferring S. alterniflora was the lowest. Of these species,most were generalist herbivores. The number of species preferring P. australis was the highest. Among these species,most were predator /parasitoid and specialist herbivore species. Herbivore species preferring Sc. triqueter were all generalists,but with relatively high indicator values. 【Conclusion 】 S. alterniflora invasion reduces the insect biodiversity and significantly changes the structural characteristics and seasonal dynamics of insect functional groups in Jiuduansha wetland. In comparison with insect herbivores,natural enemy insects are more sensitive to the effects of S. alterniflora invasion. Some generalist herbivores may have developed adaptation mechanisms to S. alterniflora. Enough attention should be paid to the potential ecological and evolutionary consequences behind these phenomena.
出处
《昆虫学报》
CAS
CSCD
北大核心
2017年第1期67-83,共17页
Acta Entomologica Sinica
基金
中国科学院战略生物资源科技支撑体系运行专项(CZBZX-1)
关键词
互花米草
昆虫
功能群
季节动态
湿地
九段沙
Spartina alterniflora
insect
functional group
seasonal dynamics
wetland
Jiuduansha