Synergistic impacts of nutrient enrichment and climate change on long-term water quality and ecological dynamics in contrasting shallow-lake zones
Synergistic impacts of nutrient enrichment and climate change on long-term water quality and ecological dynamics in contrasting shallow-lake zones
复制标题
营养盐富集和气候变化对浅湖区长期水质和生态动态的协同影响
DOI：
10.1002/lno.11878
复制
发表时间：
2021-06-23
影响因子：
4.5
通讯作者：
Shen, Ji
中科院分区：
文献类型：
--
作者：
Lin, Qi;Zhang, Ke;Shen, Ji
淡水生态系统的人为和气候压力受到全球关注。然而，在不同空间和时间尺度上作用的多种压力源（例如营养物富集、气候变暖、风向和降水变化）的相互作用和影响往往很复杂，并且仍然存在争议。在这里，我们通过将沉积光合色素和地球化学记录与水监测和历史档案相结合，重建了一个大型浅湖（中国太湖）藻类为主和水生植物为主的区域的富营养化和初级生产者群落的一个世纪动态。我们的目的是探索水质和湖泊生物群对多种环境扰动响应的长期潜在机制。我们发现，在不同的生态区，水质退化和藻类群落改变表现出相似的趋势，但时间和轨迹不同。北梅梁湾富营养化的发生和强度（20世纪50年代以来）远远超过以水生植物为主的东太湖（与1990年代相似）。人为养分取代了过去气候对光养组合的产生和组成的控制。更重要的是，湖泊浮游植物对气候变暖、风速降低和文化富营养化后的极端天气有显着的反应。湖泊生态系统中营养物质和气候的协同相互作用对于促进北湖超富营养区附近以微囊藻为主的有害藻华（HAB）变得越来越重要。异步的湖泊和生态响应也表明了湖泊生态状况和流域水文地貌特征的调节作用。总的来说，我们的研究结果表明，缓解富营养化和有害藻华需要采取三重管理策略，将人为营养物质、气候变化和湖泊流域环境结合起来。
Anthropogenic and climatic stressors on freshwater ecosystems are of global concern. However, the interactions and effects of multiple stressors (e.g., nutrient enrichment, climate warming, altered wind and precipitation) acting over different spatial and temporal scales are often complex and remain controversial. Here, we reconstructed one-century dynamics of eutrophication and primary producer communities in algal-dominated and macrophyte-dominated zones of a large shallow lake (Taihu, China), by integrating sedimentary photosynthetic pigments and geochemical records with water monitoring and historical archives. We aimed to explore the long-term underlying mechanisms of the responses of water quality and lake biota to multiple environmental perturbations. We found that water quality degradation and algal community modification showed similar trends but distinct timings and trajectories in contrasting ecological zones. Onset and intensity of eutrophication in north Meiliang Bay (since the 1950s) exceeded far beyond that of macrophyte-dominated Eastern Taihu (similar to 1990s). Anthropogenic nutrients overtook past climatic control on production and composition of phototrophic assemblages. More importantly, lake phytoplankton responded markedly to climate warming, decreasing wind speed, and extreme weathers after cultural eutrophication. Synergistic interactions of nutrients and climate on lake ecosystems became increasingly significant in promoting harmful algal blooms (HABs) dominated by Microcystis, close to the hyper-eutrophic north lake zones. The asynchronous limnological and ecological responses also indicated the modulating roles of lake ecological regime and catchment hydrogeomorphic characteristic. Collectively, our findings suggest that mitigation of eutrophication and HABs calls for a triple management strategy integrating anthropogenic nutrients, climate change, and lake-catchment setting.