Mitrani Department of Desert Ecology, Swiss Institute of Dryland Environmental and Energy Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus, 84990, Midreshet Ben-Gurion, Israel.
Laboratory of Macroecology and Biogeography of Invertebrates, Saint-Petersburg State University, University Emb. 7/9, 199034, Saint-Petersburg, Russia.
Oecologia. 2020 Apr;192(4):1057-1071. doi: 10.1007/s00442-020-04641-9. Epub 2020 Apr 4.
We studied compositional turnover in communities of fleas and mites harboured by small mammals using zeta diversity metric (similarity between multiple communities) and asked whether the patterns of zeta diversity decline with an increase in the number of communities differ between taxa and hierarchical scales [infracommunities (parasite assemblages on individual hosts), component communities (parasite assemblages harboured by host populations), and compound communities (all parasite species in a locality)]. The average number of shared species declined with an increasing number of communities (zeta order). It attained zero at higher orders in infracommunities of both taxa with the shape of the zeta decline being best fitted by the negative exponential function, and the retention rate curves being modal. In contrast, zeta diversity values for compound communities of mites and fleas did not attain zero at higher zeta orders, and the form of the zeta decline was best fitted by the power-law function, whereas the retention rate curves were asymptotic. In component communities, the form of zeta decline was best fitted by either exponential or power-law function in dependence of whether communities were considered within a host across localities or across hosts within a locality and whether ubiquitous species were taken into account. Our main conclusions are that (a) the rules governing compositional turnover in parasite communities for the lowest and the highest hierarchical scales are taxon-invariant but scale-dependent and (b) species composition of infracommunities is mainly driven by stochastic assembly processed, whereas that of compound communities is mainly driven by niche-based processes.
我们使用 zeta 多样性指标（多个群落之间的相似性）研究了小型哺乳动物携带的跳蚤和螨虫群落的组成性周转率，并询问了 zeta 多样性模式随群落数量增加而下降的模式是否在分类和层次尺度上存在差异[群落内（个体宿主上的寄生虫组合）、群落内（宿主种群中携带的寄生虫组合）和复合群落（局部所有寄生虫物种）]。共享物种的平均数量随着群落数量的增加而减少（zeta 阶）。在两个分类群的群落内，zeta 减少的形状最好通过负指数函数拟合，保留率曲线为模态，达到更高阶时为零。相比之下，螨虫和跳蚤的复合群落的 zeta 多样性值在更高的 zeta 阶时并未达到零，zeta 减少的形式最好通过幂律函数拟合，而保留率曲线则是渐近的。在群落内，zeta 减少的形式最好通过指数或幂律函数拟合，具体取决于群落是在宿主内跨局部考虑还是在宿主内跨局部考虑，以及是否考虑普遍物种。我们的主要结论是：（a）寄生虫群落组成性周转率的规则在最低和最高层次尺度上是分类不变的，但依赖于尺度；（b）群落内的物种组成主要受随机组装过程驱动，而复合群落的物种组成主要受基于生态位的过程驱动。
