Canadian Journal of Fisheries and Aquatic Sciences, Ahead of Print.
We evaluated the crustacean zooplankton size spectrum as an indicator of lake characteristics and ecosystem change. First, we used time series from seven Canadian Shield lakes to identify the factors associated with among-lake and among-year variability in the spectrum slope (relative abundance of small and large zooplankton) and centered height (total abundance). Second, we used time series from an invaded and three control lakes to assess change in mean and variability in slope and height due to a Bythotrephes invasion. We found that the slope and height reflected among-lake predictors related to morphometry. The slope was responsive to long-term declining lake phosphorus levels, whereas the height reflected both increases in dissolved organic carbon and decreases in ice duration. We detected a significant increase (i.e., flattening) in mean slope and substantial (up to 120%) increases in the CV of height after Bythotrephes invaded Harp Lake. Thus, the zooplankton size spectrum was responsive to long-term environmental change, and a strong top-down perturbation can be detected through regular and frequent monitoring programs.

中文翻译：

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在加拿大盾湖样本中评估甲壳类浮游动物群落规模谱对环境变化和外来入侵者的响应能力

《加拿大渔业和水生科学杂志》，印刷前。
我们评估了甲壳动物的浮游生物规模谱，以作为湖泊特征和生态系统变化的指标。首先，我们使用来自七个加拿大希尔德湖的时间序列来确定与光谱斜率（小型和大型浮游动物的相对丰度）和中心高度（总丰度）的湖间和年际变化相关的因素。第二，我们使用入侵湖和三个控制湖的时间序列来评估由于拜特菲斯入侵而造成的坡度和高度均值和变异性的变化。我们发现坡度和高度反映了与形态测量有关的湖间预测因子。坡度对长期减少的湖磷水平有响应，而高度反映了溶解有机碳的增加和冰期的减少。我们检测到显着增加（即，斜角侵入Harp湖之后，高度的CV显着增加（最高平缓），并且平均坡度显着提高（最高120％）。因此，浮游动物的大小谱对长期的环境变化有响应，并且可以通过定期和频繁的监测程序检测到强烈的自上而下的扰动。