新疆北部干旱区5个湿地蚊类的生态位及无倾向对应排序分析

Niche breadth,overlap,and detrended correspondence analysis of mosquitoes in five arid wetlands in North Xinjiang, China

目的应用生态位理论和方法,对新疆北部干旱区5个湿地蚊类的生态位宽度、生态位重叠及其种间关系进行研究。方法使用CO2灯诱法对各湿地蚊类进行调查采集,分类计数,测定生态位宽度及生态位重叠指数,利用各湿地生境内各蚊种的构成比构建矩阵进行系统聚类分析,并以不同湿地生境内各种蚊虫数量为指标,应用无倾向对应分析(DCA)排序法进行分析。结果新疆北部干旱区5个湿地共捕获蚊类5属16种共20 731只,分析结果显示,生态位宽度最大为背点伊蚊(0.8326),其他依次为刺扰伊蚊(0.6350)、里海伊蚊(0.5954)和米赛按蚊(0.5558);生态位重叠指数有26个种对数>0.90,占20.31%,85个种对数<0.50,占70.83%;系统聚类分析将5个湿地生境分成两类;DCA排序结果显示,新疆伊蚊和环跗曼蚊距离其他蚊种最远。结论优势种的生态位宽度不一定最大。布尔根河湿地、额尔齐斯河下游湿地及伊犁河下游湿地的蚊类群落构成较为相似,艾比湖湿地和额敏河河口湿地蚊类群落构成较为相似。DCA排序可以直观反映蚊种分布与生境间的相对关系。

Objective To determine the niche breadth, overlap, and inter-species correlations of mosquito species in five arid wetlands in North Xinjiang using ecological niche theory and relevant methods. Methods Mosquitoes were captured with carbon dioxide-baited light traps and were then classified and counted. Niche breadth and overlap were estimated with Shannon- Wiener＇ s and Pianka＇ s formulae, respectively. Hierarchical cluster analysis was performed with a matrix of the constituent ratio of individual species, and detrended correspondence analysis （DCA） was performed with the population size of each mosquito species in different wetland habitats. Results A total of 20 731 mosquitoes, belonging to 16 species in 5 genera, were captured in the five arid wetlamts in North Xinjiang. Of these, Aedes dorsalis had the greatest niche breadth （0.8326）, followed by Ae. vexans （0.6350）, Ae. caspius （0.5954）, and Anopheles messeae （0.5558）. Regarding niche overlap index, there were 26 species （20.31%） with log-transformed values above 0.90 and 85 species （70.83%） with log-transformed values above 0.50. The five wetland habitats were classified into two major ecotypes by hierarchical cluster analysis. DCA ordination diagram showed the longest distance of Ae. sinkiangensis and Mansonia richiardii from other species among the mosquitoes tested. Conclusion The dominant mosquito species does not always has the greatest niche breadth. Similar mosquito population structure exists in the wetlands of Buergen River, the lower reach of Ertix River, and the lower reach of Yili River, as well as in the wetlands of Ebinur Lake and the estuary of Emin River. Species distribution of mosquitoes and their correlations with wetland habitats can be directly reflected by DCA ordination.