1. Arctic freshwaters are facing multiple environmental pressures, including rapid climate change and increasing land___use activities. Freshwater plankton assemblages are expected to reflect the effects of these stressors through shifts in species distributions and changes to biodiversity. These changes may occur rapidly due to the short generation times and high dispersal capabilities of both phyto___ and zooplankton.
2. Spatial patterns and contemporary trends in plankton diversity throughout the circumpolar region were assessed using data from more than 300 lakes in the U.S.A. (Alaska), Canada, Greenland, Iceland, the Faroe Islands, Norway, Sweden, Finland, and Russia. The main objectives of this study were: (1) to assess spatial patterns of plankton diversity focusing on pelagic communities; (2) to assess dominant component of __ diversity (turnover or nestedness); (3) to identify which environmental factors best explain diversity; and (4) to provide recommendations for future monitoring and assessment of freshwater plankton communities across the Arctic region.
3. Phytoplankton and crustacean zooplankton diversity varied substantially across the Arctic and was positively related to summer air temperature. However, for zooplankton, the positive correlation between summer temperature and species numbers decreased with increasing latitude. Taxonomic richness was lower in the high Arctic compared to the sub___ and low Arctic for zooplankton but this pattern was less clear for phytoplankton. Fennoscandia and inland regions of Russia represented hotspots for, respectively, phytoplankton and zooplankton diversity, whereas isolated regions had lower taxonomic richness. Ecoregions with high __ diversity generally also had high __ diversity, and turnover was the most important component of __ diversity in all ecoregions.
4. For both phytoplankton and zooplankton, climatic variables were the most important environmental factors influencing diversity patterns, consistent with previous studies that examined shorter temperature gradients. However, barriers to dispersal may have also played a role in limiting diversity on islands. A better understanding of how diversity patterns are determined by colonisation history, environmental variables, and biotic interactions requires more monitoring data with locations dispersed evenly across the circumpolar Arctic. Furthermore, the importance of turnover in regional diversity patterns indicates that more extensive sampling is required to fully characterise the species pool of Arctic lakes.

中文翻译：

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北极淡水浮游植物和浮游动物多样性的首次环极评估：空间格局和环境因素

1. 北极淡水面临多重环境压力，包括快速的气候变化和不断增加的土地利用活动。预计淡水浮游生物组合将通过物种分布的变化和生物多样性的变化来反映这些压力源的影响。由于植物___和浮游动物的世代时间短且传播能力强，这些变化可能会迅速发生。
2. 使用来自美国（阿拉斯加）、加拿大、格陵兰、冰岛、法罗群岛、挪威、瑞典、芬兰和俄罗斯的 300 多个湖泊的数据评估了整个极地地区浮游生物多样性的空间模式和当代趋势。本研究的主要目标是：（1）评估浮游生物多样性的空间格局，重点是中上层群落；(2) 评估__多样性的主要成分（营业额或嵌套性）；(3) 确定哪些环境因素最能解释多样性；(4) 为未来监测和评估整个北极地区的淡水浮游生物群落提供建议。
3. 整个北极地区的浮游植物和甲壳类浮游动物多样性差异很大，并且与夏季气温呈正相关。然而，对于浮游动物，夏季温度与物种数量之间的正相关性随着纬度的增加而降低。与亚___和低北极相比，北极高地的浮游动物的分类丰富度较低，但浮游植物的这种模式不太清楚。俄罗斯的芬诺斯坎迪亚和内陆地区分别代表浮游植物和浮游动物多样性的热点，而偏远地区的分类丰富度较低。__ 多样性高的生态区一般也具有较高的 __ 多样性，而周转率是所有生态区中 __ 多样性最重要的组成部分。
4. 对于浮游植物和浮游动物来说，气候变量是影响多样性模式的最重要的环境因素，这与之前研究较短温度梯度的研究一致。然而，分散障碍也可能在限制岛屿多样性方面发挥了作用。更好地理解多样性模式是如何由殖民历史、环境变量和生物相互作用决定的，需要更多的监测数据，这些数据的位置均匀分布在整个北极圈。此外，更替在区域多样性模式中的重要性表明，需要更广泛的采样来充分表征北极湖泊的物种库。