1. Both β diversity and metacommunity structure vary in time and space. It is necessary to examine different scales, especially in the face of extreme hydrological conditions.
2. We investigated seasonal variation in β diversity and Elements of Metacommunity Structure [EMS] of zooplankton during four years (two years of prolonged drought and two years with extreme flood events) and at two spatial scales (sub-basins and floodplain; smaller and larger spatial scale, respectively).
3. We sampled 29 lakes quarterly during four years in the Upper Paraná River floodplain, Brazil. We estimated the replacement component of β diversity using the Jaccard dissimilarity index. We also used EMS to determine the metacommunity pattern of zooplankton distribution in each period and spatial scale.
4. The flood peak observed in the snapshot sampling drove the homogenization of zooplanktonic assemblages. However, β diversity was not reduced in the two years with extreme flood events compared to the period of prolonged drought at either of the spatial scales (floodplain and sub-basins), except for a single sub-basin. This finding shows the importance of longer-term ecological studies to better capture the dynamics of the zooplanktonic metacommunity.
5. Regardless of the hydrological period and spatial scale zooplanktonic metacommunity structure remained practically constant throughout the four years, with a predominance of species range turnover (Clementsian). At the smallest spatial scale (sub-basins), we found quasi-structural patterns (quasi-Clementsian and quasi-Gleasonian). The predominance of the Clementsian pattern suggests that the associations of zooplankton species in the floodplain responded similarly to the environmental gradient and that the responses differed among species groups.
6. Over time, the smaller spatial scale (sub-basin) better represents the dynamics of β diversity than the larger spatial scale (floodplain), and better represents the structure of the zooplankton metacommunity. However, we emphasize the need for further studies to consider different biological groups and larger spatial scale over time to maximize the understanding of aquatic metacommunities dynamics.

中文翻译：

---

浮游动物β多样性动态和元群落结构取决于新热带洪泛区的时空尺度

1. β多样性和元群落结构在时间和空间上都不同。有必要考察不同的尺度，尤其是在极端水文条件下。
2. 我们调查了四年（两年的长期干旱和两年的极端洪水事件）和两个空间尺度（子流域和洪泛区；越来越小的空间尺度）的 β 多样性和元群落结构元素 [EMS] 的季节性变化。规模，分别）。
3. 四年间，我们每季度对巴西巴拉那河上游泛滥平原的 29 个湖泊进行采样。我们使用 Jaccard 相异指数估计了 β 多样性的替代成分。我们还使用EMS来确定每个时期和空间尺度上浮游动物分布的元群落模式。
4. 在快照采样中观察到的洪水高峰推动了浮游动物组合的同质化。然而，与任何一个空间尺度（泛滥平原和子流域）的长期干旱时期相比，极端洪水事件的两年内β多样性并未降低，除了单个子流域。这一发现表明长期生态研究对于更好地捕捉浮游动物群落动态的重要性。
5. 无论水文时期和空间尺度如何，浮游动物群落结构在四年中几乎保持不变，物种范围更替占主导地位（Clementsian）。在最小的空间尺度（子盆地）上，我们发现了准结构模式（准克莱门斯和准格里森）。Clementsian 模式的优势表明，泛滥平原中浮游动物物种的关联对环境梯度的反应类似，并且物种组之间的反应不同。
6. 随着时间的推移，较小的空间尺度（子流域）比较大的空间尺度（泛滥平原）更好地代表了 β 多样性的动态，并且更好地代表了浮游动物群落的结构。然而，我们强调需要进一步研究以考虑随着时间的推移不同的生物群和更大的空间尺度，以最大限度地了解水生元群落动态。