The analysis of bird community assembly rules is fundamental to understand which mechanisms determine the composition of bird species in urban areas. However, the long-term variation of community assembly rules has not been analyzed yet. The objectives of this study are (1) to analyze the variation of community assembly rules along rural-urban gradients of three cities in central Argentina and (2) to compare the patterns of community assembly between two periods separated by 6 years. Bird surveys were performed along transects in urban, suburban, and rural habitats during 2011 and 2017. Departures from null models that took into account differences in species richness (standardized effect size, SES) were calculated for functional and phylogenetic diversities. A total of 57 species were recorded. Bird species richness was higher in suburban than in urban and rural habitats. SES of functional diversity increased over the years and was significantly lower in urban habitats than in rural habitats, showing a pattern of functional clustering in the most urbanized areas and functional randomness in rural ones. Phylogenetic diversity was higher in both suburban and urban habitats than rural ones, and the phylogenetic clustering in rural bird assemblages changed to randomness in suburban and urban habitats. Bird communities in urban habitats were phylogenetically random and functionally clustered, evidencing environmental filtering by urbanization. In contrast, bird communities in rural areas tended to be phylogenetically clustered, evidencing that certain clades are adapted to rural areas. The processes structuring bird communities along rural-urban gradients were consistent between the 2 years compared.

中文翻译：

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阿根廷农村-城市梯度中期鸟类群落组装的一致性

鸟类群落组装规则的分析对于了解哪些机制决定了城市地区鸟类的组成至关重要。然而，尚未分析社区集会规则的长期变化。本研究的目的是（1）分析阿根廷中部三个城市沿城乡梯度的社区集会规则的变化；（2）比较相隔 6 年的两个时期的社区集会模式。2011 年和 2017 年期间，沿城市、郊区和农村栖息地的横断面进行了鸟类调查。 计算了功能和系统发育多样性与考虑物种丰富度差异（标准化效应大小，SES）的空模型的偏差。共记录了57种。郊区鸟类物种丰富度高于城市和农村栖息地。多年来，功能多样性的 SES 在城市生境中显着低于农村生境，显示出最城市化地区的功能集群模式和农村地区的功能随机性。郊区和城市栖息地的系统发育多样性均高于农村，而郊区鸟类和城市栖息地的鸟类系统组合的系统发育聚类变为随机性。城市栖息地中的鸟类群落在系统发育上是随机的，功能上是聚集的，这证明了城市化对环境的过滤。相比之下，农村地区的鸟类群落倾向于系统发育集群，证明某些进化枝适应了农村地区。