In Mediterranean temporary ponds, the timing of annual flooding is highly variable and depends on heavy seasonal rains. Ponds can flood in the autumn, winter, or spring, and thus the environmental conditions faced by emerging zooplankton can be very different. We performed an experiment in a climatic chamber where we simulated annual variation in natural temperature and light conditions to study how differences in pond-filling season affected zooplankton assemblage composition. We sampled sediments from a temporary pond and placed them in aquariums that were filled with water during three different seasons: autumn (October), winter (January), and spring (March). Zooplankton abundance, species richness, diversity, and assemblage composition differed significantly among treatments, and post-inundation temperature and pH appeared to be the main drivers of these differences. Diversity was highest in the winter treatment. It was lower in the autumn treatment and the spring treatment, and no indicator species were present in the latter. Our results suggest that interannual variability in initial inundation conditions favours the emergence of different species and thus contributes to high species richness in the egg bank. However, climate change and/or groundwater drawdown could delay pond flooding, impoverishing the zooplankton assemblage in the long term.

中文翻译：

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填充季节的年际变化影响地中海临时池塘中的浮游动物多样性

在地中海临时池塘中，每年洪水的时间变化很大，取决于季节性强降雨。池塘可能在秋季、冬季或春季泛滥，因此新兴浮游动物面临的环境条件可能大不相同。我们在气候室中进行了一项实验，在那里我们模拟了自然温度和光照条件的年度变化，以研究池塘填充季节的差异如何影响浮游动物组合的组成。我们从临时池塘中取样沉积物，并将它们放入在三个不同季节注满水的水族箱中：秋季（10 月）、冬季（1 月）和春季（3 月）。浮游动物丰度、物种丰富度、多样性和组合组成在处理之间存在显着差异，淹没后的温度和 pH 值似乎是这些差异的主要驱动因素。冬季处理的多样性最高。秋季处理和春季处理较低，后者无指示种存在。我们的结果表明，初始淹没条件的年际变化有利于不同物种的出现，从而导致卵库中物种的高度丰富。然而，气候变化和/或地下水下降可能会延迟池塘洪水，从长远来看会使浮游动物群落变得贫乏。我们的结果表明，初始淹没条件的年际变化有利于不同物种的出现，从而导致卵库中物种的高度丰富。然而，气候变化和/或地下水下降可能会延迟池塘洪水，从长远来看会使浮游动物群落变得贫乏。我们的结果表明，初始淹没条件的年际变化有利于不同物种的出现，从而导致卵库中物种的高度丰富。然而，气候变化和/或地下水下降可能会延迟池塘洪水，从长远来看会使浮游动物群落变得贫乏。