Freshwater ecosystems are of the most diverse ecosystems in the world, but anthropogenic disturbance and climate change are threatening the biodiversity of these habitats, particularly in the highly vulnerable arid regions. Understanding the compositional patterns in aquatic biota and discovering factors responsible for these patterns enable researchers to predict the impacts of environmental changes and reduce their destructive effects. As a first step for evaluating the conservation value of freshwater ecosystems in the arid areas of Central Iran, we investigated the phylogenetic beta diversity of Odonata assemblages and their response to climate, landscape, and local predictors. A total of 41 water bodies were surveyed and 42 species of Odonata were recorded. The distance matrices related to the total phylogenetic beta diversity of Odonata and the replacement and richness difference components were computed. Each of the three dissimilarity matrices were modelled by generalized dissimilarity modelling (GDM). The average phylogenetic beta diversity was high, and the replacement component had a higher contribution rather than the richness difference component. GDMs results showed that total phylogenetic beta diversity was strongly associated with climate and local predictors. The most influential variables observed were climate variables. Our findings indicated that even in extreme conditions, the freshwater ecosystems could support species with various phylogenetic histories. We emphasize the importance of man-made water bodies in supporting freshwater biodiversity in arid areas. Given the growing threat of habitat degradation and climate change, with no conservation plan, many vulnerable species may be in danger of localized extinction within the region.

淡水生态系统是世界上最多样化的生态系统，但是人为干扰和气候变化正在威胁这些生境的生物多样性，特别是在高度脆弱的干旱地区。了解水生生物的组成模式并发现造成这些模式的因素，使研究人员能够预测环境变化的影响并减少其破坏作用。作为评估伊朗中部干旱地区淡水生态系统保护价值的第一步，我们调查了Odonata组合的系统发育β多样性及其对气候，景观和当地预报因子的响应。总共调查了41个水体，并记录了42种Odonata。计算了与Odonata的总系统发生β多样性有关的距离矩阵，以及替代和丰富度差异成分。通过通用差异模型（GDM）对这三个差异矩阵进行建模。系统发育平均β多样性较高，替代成分的贡献度要高于富裕度差异成分。GDM的结果表明，总的系统发生β多样性与气候和当地预测因素密切相关。观察到的最具影响力的变量是气候变量。我们的发现表明，即使在极端条件下，淡水生态系统也可以支持具有各种系统发生历史的物种。我们强调人造水体在支持干旱地区淡水生物多样性方面的重要性。