Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, 46.7 km of Athens-Sounio Ave., 19013 Anavyssos, Attica, Greece; Department of Biology, University of Patras, University Campus Rio, GR 26500 Patras, Greece.
Hellenic Centre for Marine Research, Institute of Marine Biological Resources and Inland Waters, 46.7 km of Athens-Sounio Ave., 19013 Anavyssos, Attica, Greece.
Sci Total Environ. 2022 Jul 15;830:154709. doi: 10.1016/j.scitotenv.2022.154709. Epub 2022 Mar 21.
Lakes are particularly vulnerable ecosystems to global warming. Surface temperature of most lakes in the world has significantly increased. Here, we analysed time-series of water temperature, mixing-depth, and ice depth of 51 European lakes over the last four decades. We used data of surface temperature, total layer water temperature, mix-layer temperature, mix-layer depth, and ice cover depth obtained from the ERA5-Land reanalysis dataset. Our main objectives were a) to identify significant changes of the examined variables that have occurred from 1981 to 2019 and b) to assess the variability of changes in relation with geographical and lake morphological gradients. To this end, time series analysis was conducted using generalized additive models (GAMs). In addition, we quantified the magnitude of change by estimating the Sen's slopes for each variable and then we examined the variability of these slopes to geographical and lake morphological parameters using GAMs. Our results confirmed that water temperature parameters (surface, total-layer and mix-layer temperature) have significantly increased for all lakes during the last four decades. We also found significant changes of the mixing depth for 14 lakes. In addition, the lake ice depth has significantly decreased in all fifteen lakes of the subarctic climate region. Finally, we showed that the Sen's slopes depend on the geographic coordinates and the elevation of the lakes, whereas lake morphometry (e.g. depth) has a smaller effect on the magnitude of changes. These findings hint that lake ecosystems of Europe have substantially changed over the last forty years and urge the need to take precautionary measures to prevent future implications for the freshwater biota.
湖泊是对全球变暖特别脆弱的生态系统。世界上大多数湖泊的表面温度都显著升高。在这里，我们分析了过去四十年中 51 个欧洲湖泊的水温、混合深度和冰深的时间序列。我们使用了 ERA5-Land 再分析数据集获取的表面温度、总层水温、混合层温度、混合层深度和冰盖深度数据。我们的主要目标是：a）确定从 1981 年到 2019 年发生的被检查变量的显著变化；b）评估与地理和湖泊形态梯度相关的变化的可变性。为此，使用广义加性模型（GAMs）进行时间序列分析。此外，我们通过估计每个变量的 Sen 斜率来量化变化的幅度，然后使用 GAMs 检查这些斜率与地理和湖泊形态参数的可变性。我们的结果证实，所有湖泊的水温参数（表面、总层和混合层温度）在过去四十年中都显著升高。我们还发现 14 个湖泊的混合深度发生了显著变化。此外，亚北极气候区的 15 个湖泊的湖冰深度都显著下降。最后，我们表明 Sen 斜率取决于地理坐标和湖泊的海拔，而湖形态（例如深度）对变化幅度的影响较小。这些发现表明，欧洲的湖泊生态系统在过去四十年中发生了重大变化，需要采取预防措施，以防止对淡水生物群产生未来影响。
