Regev Shajar, Carmel Yohay, Schlabing Dirk, Gal Gideon
Kinneret Limnological Laboratory, Israel Oceanographic and Limnological Research, Migdal 14950000, Israel; Faculty of Civil and Environmental Engineering, The Technion-Israel Institute of Technology, Haifa 3200003, Israel.
Faculty of Civil and Environmental Engineering, The Technion-Israel Institute of Technology, Haifa 3200003, Israel.
Sci Total Environ. 2024 Apr 15;921:171163. doi: 10.1016/j.scitotenv.2024.171163. Epub 2024 Feb 23.
Climate change is anticipated to alter lake ecosystems by affecting water quality, potentially resulting in loss of ecosystem services. Subtropical lakes have high temperatures to begin with and are expected to exhibit higher temperatures all year round which might affect the thermal structure and ecological processes in a different manner than lakes in temperate zones. In this study the ecosystem response of the sub-tropical Lake Kinneret to climate change was explored using lake ecosystem models. Projection reliability was increased by using a weather generator and ensemble modelling, confronting uncertainty of both climate projections and lake models. The study included running two 1D hydrodynamic-biogeochemical models over one thousand realizations of two gradual temperature increase scenarios that span over 49 years. Our predictions show that an increase in air temperature would have subtle effects on stratification properties but may result in considerable changes to biogeochemical processes. Water temperature rise would cause a reduction in dissolved oxygen. Both of these changes would produce elevated phosphate and lowered ammonium concentrations. In turn, these changes are predicted to modify the phytoplankton community, expressed chiefly in increased cyanobacteria blooms at the expense of green phytoplankton and dinoflagellates; these changes may culminate in overall reduction of primary production. Identification of these trends would not be possible without the use of many realizations of climate scenarios. The use of ensemble modelling increased prediction reliability and highlighted elements of uncertainty. Though we use Lake Kinneret, the patterns identified most likely indicate processes that are expected in sub-tropical lakes in general.
气候变化预计会通过影响水质改变湖泊生态系统，可能导致生态系统服务功能丧失。亚热带湖泊原本温度就高，预计全年温度还会更高，这可能会以与温带湖泊不同的方式影响热结构和生态过程。在本研究中，利用湖泊生态系统模型探究了亚热带基奈雷特湖对气候变化的生态系统响应。通过使用天气发生器和集合建模提高了预测可靠性，应对了气候预测和湖泊模型的不确定性。该研究包括在49年的两个逐渐升温情景的一千次实现上运行两个一维水动力 - 生物地球化学模型。我们的预测表明，气温升高对分层特性影响细微，但可能导致生物地球化学过程发生显著变化。水温上升会导致溶解氧减少。这两个变化都会导致磷酸盐浓度升高和铵浓度降低。反过来，这些变化预计会改变浮游植物群落，主要表现为蓝藻水华增加，以绿藻和甲藻为代价；这些变化可能最终导致初级生产力总体下降。如果不使用许多气候情景实现，就不可能识别出这些趋势。集合建模的使用提高了预测可靠性，并突出了不确定性因素。尽管我们以基奈雷特湖为例，但所识别出的模式很可能普遍表明了亚热带湖泊中预期会出现的过程。
