Shallow lakes in subtropical climate regions may have a clear water state with a predominance of submerged or floating macrophytes and a turbid water state with a predominance of phytoplankton. The relationship between microcrustaceans and these changes in alternative states is still incipient in the literature. And to better understand these relationships, the functional approach is an excellent tool. Thus, the present work seeks to test the hypothesis that changes in alternative stable states over time reflect the variability of composition and functional diversity of microcrustaceans. For this, samples of microcrustaceans collected in a subtropical shallow lake, which underwent alternate state changes in the period to 2000–2014, were used. Our results demonstrate a variation in composition and functional diversity among alternative states, thus supporting our hypothesis. In periods of clear water with a predominance of floating macrophytes, we found a greater functional diversity and richness of genera. This result may be associated with several factors such as greater habitat heterogeneity and lower predation pressure. The lowest values of functional diversity found in periods of turbid waters with predominance of phytoplankton and periods of clear waters with submerged macrophytes are related to the dominance of functional traits, such as scraper feeding type, herbivorous/omnivorous trophic group, littoral habitat and asexual reproduction. These traits are functional features of most Ostracoda genera, a taxonomic group abundant in these two alternative states. The predominance of this group may be related to the environmental characteristics of these periods, such as the high vegetation cover and the availability of niches unoccupied by more sensitive species, since most Ostracoda have high environmental tolerance. We conclude that the functional traits approach combined with taxonomic groups respond to temporal variations of alternative stable states and are important tools to detect environmental changes.

中文翻译：

---

交替稳定状态的交替影响亚热带浅湖中小甲壳类动物的功能多样性

亚热带气候区的浅水湖泊可能呈现以沉水或漂浮的大型植物为主的清澈水态和以浮游植物为主的浑浊水态。微甲壳动物与这些替代状态变化之间的关系在文献中仍处于初期阶段。为了更好地理解这些关系，函数式方法是一个很好的工具。因此，目前的工作试图检验这样一个假设，即随着时间的推移，替代稳定状态的变化反映了微甲壳动物的组成和功能多样性的可变性。为此，使用了在亚热带浅湖中采集的微甲壳类动物样本，该湖在 2000 年至 2014 年期间经历了交替的状态变化。我们的结果证明了替代状态之间的组成和功能多样性的变化，从而支持我们的假设。在以漂浮大型植物为主的清水时期，我们发现了更大的功能多样性和属的丰富度。这一结果可能与几个因素有关，例如更大的栖息地异质性和较低的捕食压力。在以浮游植物为主的混浊水域和以沉水植物为主的清澈水域中发现的功能多样性最低值与功能性状的优势有关，例如刮板摄食类型、草食性/杂食性营养群、沿海生境和无性繁殖. 这些特征是大多数介形虫属的功能特征，这是在这两个替代状态中丰富的分类群。这个群体的优势可能与这些时期的环境特征有关，例如高植被覆盖和更敏感物种未占据的生态位的可用性，因为大多数介形类动物具有很高的环境耐受性。我们得出的结论是，功能特征方法与分类群相结合可以响应替代稳定状态的时间变化，并且是检测环境变化的重要工具。