Long- and short-term effects of climate variability and physical forcing on the diversity of aquatic organisms

北方半球的气候变化很大程度上与大气环流有关，例如北大西洋涛动。近年来，许多研究揭示了NAO对不同生态系统中生物动态的影响，特别是对生活史事件发生的时间、生物量以及不同营养级生物量的影响。然而，没有研究对NAO如何影响生物多样性提出一致的看法。在这里，我们提出了一个独特的研究，旨在分析水生生物群落多样性的长期数据，结合预测水生生物多样性的趋势，同时解开气候变化的长期和短期影响。为了实现这一目标，我们将联合收割机数据库从不同的海洋和淡水生态系统在中北部欧洲。这些数据库提供了从湖泊、溪流和2个海洋站点的物种丰度和群落组成的长期时间序列，包括从德国到北方瑞典的空间范围。我们将利用这些数据来检验：1）与气候变化相关的水生群落多样性是否存在年代际或年度趋势。2)物种特异性反应的多样性是否导致与气候变率相关的群落模式的变化，包括相互作用生物的季节性共同出现的变化（匹配-不匹配）的信息，以及3）气候的短期变率是否对干扰的生态时间框架中的多样性产生影响。我们将利用这些信息来预测气候变化情景下未来生物多样性的变化。这项研究将导致气候强迫对水生生物多样性的作用的建模和实验方法。

Climate variations over the Northern Hemisphere are to a substantial proportion associated with atmospheric circulations, e.g. the North Atlantic Oscillation (NAO). Recently, many studies have revealed the impact of the NAO on the dynamics of organisms in different ecosystems, especially on the timing of life history events, on the biomass of organisms, and on the biomass of different trophic levels. However, no study has developed a consistent picture on how the NAO affects biodiversity. Here we propose a unique study aiming at analysing long-term data on the diversity of aquatic communities in combination with the prediction of trends in aquatic biodiversity while disentangling long-term and short-term effects of climate variability. To achieve this goal, we will combine databases from different marine and freshwater ecosystems in North-Central Europe. These databases provide long-term time series of species abundance and community composition from lakes, streams and 2 marine sites, comprising a spatial extent from Germany to Northern Sweden. We will use these data to test: 1)Whether there are decadal or yearly trends in the diversity of aquatic communities related to climate variability. 2) Whether asynchrony of species-specific responses leads to shifting community patterns related to climate variability, including information on shifts in seasonal co-occurrence of interacting organisms (match-mismatch), and 3) Whether the short-term variability of climate has an effect on diversity in the ecological time frame of disturbances. We will use this information to predict changes in future biodiversity under changed climate scenarios. This study will result in modelling and experimental approaches to the role of climate forcing for aquatic biodiversity.