Novel Biogeochemical Pathways, Patterns and Measurements of Nitrogen and Phosphorus in Lakes and Reservoirs

湖泊和水库中氮和磷的新生物地球化学途径、模式和测量

• 批准号: RGPIN-2017-06457
• 负责人: Hudson, Jeff
• 金额: $ 1.75万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=631649
• 关键词: Novel; Biogeochemical; Pathways; Patterns; Measurements

This proposal examines the abiotic and biotic factors, including human, that affect biogeochemical processes and water quality in aquatic ecosystems. The factors giving rise to cyanobacterial blooms and their toxins are under intense research. Concern over the loss of ecosystem services (e.g., water quality) has been a major focus. However, only recently has the effect of cyanobacteria on ecosystem function been considered. Cyanobacteria have widespread impacts on food webs through toxin production, resistance to grazing and as poor food quality for grazers. Hence, when lakes are dominated by cyanobacteria their planktonic food webs should be functioning inefficiently. I will test this hypothesis with novel techniques that directly measure food web turnover efficiency. My next objective is to compare two important biogeochemical pathways of P in Lake Diefenbaker (SK). Loading of P from rivers into reservoirs is often a major determinant of water quality. Similarly, planktonic P regeneration is known to be important to maintain productivity. However, the importance of each pathway relative to the other is unknown, despite the potential significance of these processes for lake and reservoir management. Therefore, I propose to measure and compare both pathways in Lake Diefenbaker. My third objective is to determine whole-lake rates of photoammonification. This is a process by which dissolved organic nitrogen (DON) is photodecomposed to the bioavailable nutrient NH

该提案审查了影响水生生态系统中生物地球化学过程和水质的非生物和生物因素，包括人类因素。引起蓝藻水华的因素及其毒素正在紧张的研究中。对生态系统服务丧失的关切（例如，水质）一直是一个主要焦点。然而，直到最近才考虑到蓝藻对生态系统功能的影响。蓝细菌通过产生毒素、抵抗放牧和作为食草动物的劣质食物对食物网产生广泛影响。因此，当湖泊被蓝藻所控制时，它们的浮游食物网应该是低效的。我将测试这个假设与新的技术，直接测量食物网周转效率。我的下一个目标是比较两个重要的磷在迪芬贝克湖（SK）的地球化学途径。从河流到水库的磷负荷通常是水质的主要决定因素。类似地，已知磷素营养的再生对于维持生产力是重要的。然而，每个路径相对于其他的重要性是未知的，尽管这些过程的湖泊和水库管理的潜在意义。因此，我建议在迪芬贝克湖测量和比较这两种途径。我的第三个目标是确定整个湖泊的光氨化率。这是一个溶解有机氮（DON）被光分解为生物可利用营养素NH的过程