Quantifying the impact of anthropogenic nutrient imbalance on C flux from freshwater lakes: cellular mechanisms, community assembly and modelling

量化人为营养失衡对淡水湖泊碳通量的影响：细胞机制、群落组装和建模

• 批准号: NE/X005062/1
• 负责人: Yin Chen
• 金额: $ 78.21万
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX005062%2F1
• 关键词: Quantifying; impact; anthropogenic; nutrient; imbalance

Freshwater lakes are amongst the largest ecosystems on Earth, and a major contributor to both carbon dioxide (CO2) and methane (CH4) emissions, two potent greenhouse gases. The use of nitrogen-rich fertilisers and their runoff as a result of human population growth are major contributors to the growing imbalance of nitrogen (N) and phosphorus (P) in freshwater lakes. These key nutrients limit the growth of algae, the energy available to support aquatic wildlife, and greenhouse gas release from this ecologically important ecosystem at a global scale. The much faster increase of anthropogenic nitrogen runoff has dwarfed the input of phosphorus and shifted the balance of the global N:P ratio from 19:1 to 30:1 in the past four decades, driving more and more lake ecosystems towards being limited by the availability of phosphorus. Although this trend is likely to continue, our knowledge of how this will affect the movement of CO2 and CH4 within freshwater ecosystems, and between these ecosystems and the atmosphere, remains uncertain. Capitalising on our recent discovery that a low availability of P appears to reduce the capacity of both cyanobacteria (sometimes called "blue-green algae") to process CO2 and methanotrophs (a group of bacteria) to process CH4, we propose to uncover how N:P imbalance affects freshwater microbial communities and greenhouse gas emissions in freshwater lakes; effects that have major implications for global climate change.

淡水湖是地球上最大的生态系统之一，也是二氧化碳 (CO2) 和甲烷 (CH4) 这两种强效温室气体排放的主要来源。富氮肥料的使用及其因人口增长而产生的径流是淡水湖泊中氮 (N) 和磷 (P) 日益失衡的主要原因。这些关键营养物质限制了藻类的生长、支持水生野生动物的能量以及全球范围内这个生态重要生态系统的温室气体释放。人为氮径流的快速增加使磷的输入量相形见绌，并使全球氮磷比在过去四十年中从19:1转变为30:1，推动越来越多的湖泊生态系统受到磷可用性的限制。尽管这种趋势可能会持续下去，但我们对这将如何影响二氧化碳和甲烷在淡水生态系统内以及这些生态系统与大气之间的移动的了解仍然不确定。我们最近发现，磷的利用率低似乎会降低蓝藻（有时称为“蓝绿藻”）处理二氧化碳和甲烷氧化菌（一组细菌）处理甲烷的能力，我们建议揭示氮：磷不平衡如何影响淡水微生物群落和淡水湖中的温室气体排放；对全球气候变化有重大影响的影响。