Centre for Ecology & Hydrology, Lancaster Environment Centre, Lancaster, UK.
Biological and Environmental Sciences, Faculty of Natural Sciences, University of Stirling, Stirling, UK.
Glob Chang Biol. 2018 Nov;24(11):5044-5055. doi: 10.1111/gcb.14396. Epub 2018 Aug 24.
Blooms of cyanobacteria are a current threat to global water security that is expected to increase in the future because of increasing nutrient enrichment, increasing temperature and extreme precipitation in combination with prolonged drought. However, the responses to multiple stressors, such as those above, are often complex and there is contradictory evidence as to how they may interact. Here we used broad scale data from 494 lakes in central and northern Europe, to assess how cyanobacteria respond to nutrients (phosphorus), temperature and water retention time in different types of lakes. Eight lake types were examined based on factorial combinations of major factors that determine phytoplankton composition and sensitivity to nutrients: alkalinity (low and medium-high), colour (clear and humic) and mixing intensity (polymictic and stratified). In line with expectations, cyanobacteria increased with temperature and retention time in five of the eight lake types. Temperature effects were greatest in lake types situated at higher latitudes, suggesting that lakes currently not at risk could be affected by warming in the future. However, the sensitivity of cyanobacteria to temperature, retention time and phosphorus varied among lake types highlighting the complex responses of lakes to multiple stressors. For example, in polymictic, medium-high alkalinity, humic lakes cyanobacteria biovolume was positively explained by retention time and a synergy between TP and temperature, while in polymictic, medium-high alkalinity, clear lakes only retention time was identified as an explanatory variable. These results show that, although climate change will need to be accounted for when managing the risk of cyanobacteria in lakes, a "one-size fits-all" approach is not appropriate. When forecasting the response of cyanobacteria to future environmental change, including changes caused by climate and local management, it will be important to take this differential sensitivity of lakes into account.
蓝藻水华是当前全球水安全的威胁，预计未来由于营养物质富化、温度升高和极端降水与长时间干旱相结合，这种威胁还将加剧。然而，对于多重胁迫的响应往往很复杂，而且关于它们如何相互作用的证据相互矛盾。在这里，我们使用了来自中欧和北欧 494 个湖泊的广泛数据，评估了蓝藻如何响应不同类型湖泊中的营养物质（磷）、温度和水滞留时间。根据决定浮游植物组成和对营养物质敏感性的主要因素的析因组合，检查了八种湖泊类型：碱度（低和中高）、颜色（清澈和腐殖质）和混合强度（多湖和分层）。与预期一致，在八种湖泊类型中的五种中，蓝藻随着温度和滞留时间的增加而增加。在纬度较高的湖泊类型中，温度的影响最大，这表明目前没有风险的湖泊可能会受到未来变暖的影响。然而，蓝藻对温度、滞留时间和磷的敏感性在湖泊类型之间存在差异，突出了湖泊对多种胁迫的复杂响应。例如，在多湖、中高碱度、腐殖质湖泊中，蓝藻生物量与滞留时间呈正相关，与 TP 和温度之间存在协同作用，而在多湖、中高碱度、清澈湖泊中，只有滞留时间被确定为解释变量。这些结果表明，尽管在管理湖泊蓝藻风险时需要考虑气候变化，但“一刀切”的方法是不合适的。在预测蓝藻对未来环境变化的响应时，包括气候变化和当地管理引起的变化，考虑湖泊的这种差异敏感性将非常重要。
