Body size is an important functional trait that can be indicative of ecosystem structure and constraints on growth. Both increasing temperatures and eutrophication of lakes have been associated with a shift toward smaller zooplankton taxa. This is important in the context of climate change, as most aquatic habitats are expected to warm over the coming decades. Our study uses data from over 1000 lakes surveyed across a range of latitudes (26–49°N) and surface temperatures (10–35°C) in the USA during the spring/summer of 2012 to characterize pelagic cladoceran body size distributions. We used univariate and multiple regression modeling to determine which environmental parameters were strongly correlated to cladoceran body size. A strong positive correlation was observed between cladoceran body size and latitude, while a strong negative correlation was observed between cladoceran body size and water temperature. The ratio of zooplankton to phytoplankton, as well as relative total biomass contributions by cladocerans, decreased as trophic state increased. Multiple regression identified temperature-related variables and water clarity as significantly affecting cladoceran body size. These observations demonstrate the dual threat of climate change and eutrophication on lake ecosystems and highlight potential changes in biogeographical patterns of zooplankton as lakes warm.

中文翻译：

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在美国本土，枝ado体的大小沿温度和营养梯度分布

体型是一个重要的功能特征，可以指示生态系统结构和生长限制。升高的温度和湖泊的富营养化都与向较小的浮游生物类群转变有关。在气候变化的背景下，这一点很重要，因为预计大多数水生生境在未来几十年会变暖。我们的研究使用了2012年春季/夏季美国1000多个湖泊的数据，这些湖泊在不同纬度（26–49°N）和地表温度（10–35°C）范围内进行了调查，以表征中上层锁骨的体型分布。我们使用单变量和多元回归模型来确定哪些环境参数与锁骨的身体大小密切相关。锁骨的体型与纬度之间存在很强的正相关性，而枝ado大小与水温之间存在极强的负相关性。随着营养状态的增加，浮游动物与浮游植物的比率，以及锁骨的相对总生物量贡献也降低了。多元回归确定与温度相关的变量和水的澄清度对锁骨的大小有显着影响。这些观测结果表明了气候变化和富营养化对湖泊生态系统的双重威胁，并突出了随着湖泊变暖，浮游生物的生物地理格局可能发生的变化。多元回归确定与温度相关的变量和水的澄清度对锁骨的大小有显着影响。这些观察结果表明了气候变化和富营养化对湖泊生态系统的双重威胁，并突出了随着湖泊变暖，浮游生物的生物地理格局可能发生的变化。多元回归确定与温度相关的变量和水的澄清度对锁骨的大小有显着影响。这些观察结果表明了气候变化和富营养化对湖泊生态系统的双重威胁，并突出了随着湖泊变暖，浮游生物的生物地理格局可能发生的变化。