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

北半球的气候变化在很大程度上与大气环流有关，例如北大西洋涛动(NAO)。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、生物生物量和不同营养水平的生物量的影响。然而，关于NAO如何影响生物多样性，还没有研究得出一致的图景。在这里，我们提出了一项独特的研究，目的是分析水生群落多样性的长期数据，同时预测水生生物多样性的趋势，同时理清气候变化的长期和短期影响。为了实现这一目标，我们将结合中北欧不同海洋和淡水生态系统的数据库。这些数据库提供了湖泊、溪流和两个海洋地点的物种丰度和群落组成的长期时间序列，包括从德国到瑞典北部的空间范围。我们将使用这些数据来检验：1)水生群落多样性是否存在与气候变异性有关的年代际或年际趋势。2)特定物种反应的不同步是否导致与气候变异性有关的群落格局的变化，包括关于相互作用的生物体季节性共生的变化的信息(匹配-不匹配)，以及3)气候的短期变异性是否对干扰的生态时间框架内的多样性产生影响。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。这项研究将导致对气候强迫对水生生物多样性的作用进行建模和实验。

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.