Understanding the mechanisms that drive the assembly of communities is a central goal in ecology, and phylogenetic approaches allows for the testing of hypotheses related to such mechanisms. We analyzed assembly mechanisms of cricetid rodents in an environmentally heterogeneous region of southern Mexico by assessing their phylogenetic diversity and testing environmental predictors of the phylogenetic structure of local communities. We expected different assembly mechanisms among subprovinces according to their environmental heterogeneity. To test this, we obtained potential communities in cells of 100 km 2 by overlapping potential distribution models of 49 species of cricetids. We also estimated a phylogenetic tree using sequences of Cytb obtained from GenBank and used null models to estimate the phylogenetic diversity of communities. We found two phylogenetic diversity patterns: overdispersion in lowlands and clustering in mountains. However, for the majority of the cells, the observed phylogenetic diversity does not differ from that of null models, suggesting that stochastic processes are the main drivers of the Cricetid communities. Only 25% of the communities located in the Sierra Madre de Oaxaca exhibited significant phylogenetic clustering, indicating that habitat filtering structures their composition. According to Generalized Additive Models, all environmental variables (elevation, temperature, precipitation, net primary productivity, and potential evapotranspiration) were highly significant predictors of phylogenetic diversity. Communities at lowest elevations and warmest temperatures showed the highest phylogenetic diversity values. Despite the role of environmental factors and low vagility of cricetids, our results showed that stochastic processes explained the assembly of communities more than deterministic ones, although in mountainous areas habitat filtering was also an outstanding mechanism. This study highlights the importance of including phylogenetic information to understand the mechanisms by which communities of small mammals are assembled.

中文翻译：

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墨西哥南部仓鼠系统发育多样性的组装机制和环境预测因子

了解驱动群落组装的机制是生态学的核心目标，系统发育方法允许测试与此类机制相关的假设。我们通过评估它们的系统发育多样性和测试当地社区系统发育结构的环境预测因子，分析了墨西哥南部环境异质地区的仓鼠的组装机制。根据环境异质性，我们预计子省之间存在不同的组装机制。为了测试这一点，我们通过重叠 49 种仓鼠的潜在分布模型获得了 100 km 2 细胞中的潜在群落。我们还使用从 GenBank 获得的 Cytb 序列估计了系统发育树，并使用无效模型来估计群落的系统发育多样性。我们发现了两种系统发育多样性模式：低地过度分散和山区聚集。然而，对于大多数细胞，观察到的系统发育多样性与空模型的系统发育多样性没有区别，这表明随机过程是 Cricetid 群落的主要驱动因素。位于瓦哈卡马德雷山脉的群落中只有 25% 表现出显着的系统发育聚类，表明栖息地过滤构造了它们的组成。根据广义加性模型，所有环境变量（海拔、温度、降水、净初级生产力和潜在蒸散量）都是非常重要的系统发育多样性预测因子。海拔最低和温度最高的群落显示出最高的系统发育多样性值。尽管环境因素的作用和仓鼠的低波动性，我们的结果表明，随机过程比确定性过程更能解释群落的组装，尽管在山区栖息地过滤也是一个突出的机制。这项研究强调了包括系统发育信息以了解小型哺乳动物群落组装机制的重要性。