Abstract：
We inferred the patterns of co-occurrence of flea species in compound (across all host species) and component (across conspecific hosts) communities from six regions of the world (Mongolia, Northwest Argentina, Argentinian Patagonia, West Siberia, Slovakia, and South Africa) using the novel eigenvector ellipsoid method. This method allows us to infer structural community patterns by comparing species\' environmental requirements with the pattern of their co-occurrences. We asked whether: (a) communities are characterized by species segregation, nestedness, or modularity; (b) patterns detected by the novel method conform to the patterns identified by traditional methods that search for non-randomness in community structure; and (c) the pattern of flea species co-occurrences in component communities is associated with host species traits. The results of the application of the eigenvector ellipsoid method suggested that the co-occurrence of flea species was random in all compound communities except in South Africa, where this community demonstrated a tendency to be nested. Flea species co-occurrences were random in many component communities. Species segregation was detected in the flea community of one host, whereas the flea communities of 14 hosts from different regions appeared to be nested. No indication of a modular structure in any community was found. The nestedness of flea component communities was mainly characteristic of hosts with a low relative brain mass. We concluded that the application of this novel method that combines data on species distribution and their environmental requirements allows better identification of the community structural patterns and produces more reliable results as compared with traditional methods.
摘要：
我们推断了来自世界六个地区（蒙古，阿根廷西北部,阿根廷巴塔哥尼亚,西西伯利亚,斯洛伐克,和南非)使用新的特征向量椭球法。这种方法使我们能够通过比较物种的环境要求与它们共同出现的模式来推断结构群落模式。我们询问是否：（a）社区的特征是物种隔离，嵌套，或模块化；（b）通过新方法检测到的模式符合通过搜索群落结构中的非随机性的传统方法识别的模式；（c）组成群落中跳蚤物种共同出现的模式与宿主物种特征有关。特征向量椭球方法的应用结果表明，除南非外，所有复合群落中跳蚤物种的共同出现都是随机的，这个社区表现出嵌套的倾向。跳蚤物种在许多组成群落中同时出现是随机的。在一个宿主的跳蚤群落中发现了物种隔离，而来自不同地区的14个宿主的跳蚤群落似乎是嵌套的。在任何社区中都没有发现模块化结构的迹象。跳蚤组成群落的嵌套主要是相对脑质量较低的宿主的特征。我们得出的结论是，与传统方法相比，这种结合物种分布数据及其环境要求的新颖方法的应用可以更好地识别群落结构模式，并产生更可靠的结果。
