Algal blooms in lakes and reservoirs can be considered regime shifts from a clear‐water to algae‐dominated state that often occurs abruptly. Under experimental conditions, these regime shifts have been predicted from rises in variance and autocorrelation (generic resilience indicators) of state variables monitored at a high frequency. The goal of this study was to evaluate the behavior of resilience indicators prior to a critical transition in lakes that naturally experience algal blooms. Ambient lake conditions provide several potential hurdles that could inhibit the detection of meaningful changes in resilience indicators prior to a critical transition such as stochastic nutrient loading, spatial complexity, and decreased resilience due to higher baseline nutrient concentrations. We compiled five lake‐years of high‐frequency monitoring of chlorophyll a, phycocyanin, dissolved oxygen, and pH from four hypereutrophic lakes. Despite the factors that might hinder detecting statistical indicators of changing resilience in hypereutrophic ecosystems, we found that a rise in resilience indicators did occur prior to a critical transition in three out of four possible lake‐years, with rise beginning between 5 and 33 d prior. In one lake‐year, a critical transition occurred soon after the monitoring began, preventing detection of rising variance or autocorrelation signals which are calculated using a 21‐d rolling window. These results add to the growing body of evidence that rises in resilience indicators can be detected in ecosystems prior to a regime shift if monitoring programs are properly designed to capture the dynamics; however, continued research is needed to better understand the conditions under which resilience indicators may be useful as an early warning detection tool for lake management.

中文翻译：

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在浅水富营养化湖泊中发现藻华之前的复原力统计指标变化

湖泊和水库中的藻华可以认为是从清水状态转变为藻类为主的状态，这种状态经常突然发生。在实验条件下，已经根据高频监测的状态变量的方差和自相关（一般弹性指标）的增加来预测这些状态变化。这项研究的目的是在自然经历藻华的湖泊中，在关键转变之前评估复原力指标的行为。周围的湖泊条件提供了一些潜在的障碍，这些障碍可能会阻止在关键转变之前检测到韧性指标的有意义的变化，例如随机养分装载，空间复杂性以及由于更高的基线养分浓度而导致的韧性下降。一种，藻蓝蛋白，溶解氧和来自四个富营养化湖泊的pH值。尽管有可能阻碍检测富营养化生态系统中恢复力变化的统计指标的因素，但我们发现，在关键过渡期之前的四分之三可能的湖年中，恢复力指标的确确实发生了升高，其升高始于前5到33 d 。在一个湖年中，监测开始后不久就发生了关键转变，从而阻止了使用21d滚动窗口计算的上升方差或自相关信号的检测。这些结果增加了越来越多的证据，即如果适当设计监测程序以捕获动态，则可以在政权转移之前在生态系统中检测到恢复力指标的上升；然而，