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/X00497X/1
• 负责人: Eleanor Mackay
• 金额: $ 117.46万
• 依托单位: UK CENTRE FOR ECOLOGY & HYDROLOGY
• 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%2FX00497X%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.

淡水湖泊是地球上最大的生态系统之一，也是二氧化碳（CO2）和甲烷（CH4）排放的主要贡献者，这是两种有效的温室气体。富含氮的肥料及其径流的使用是人口增长的结果，这是淡水湖中氮（N）和磷（P）的不平衡的主要原因。这些关键营养素限制了藻类的生长，支持水生野生动植物的能量，以及在全球范围内从生态上重要的生态系统中释放的温室气体。人为氮径流的更快增加使磷的输入相形见var，并将全局n：p比率的平衡从过去四十年的19：1到30：1转移，推动了越来越多的湖泊生态系统驱动到受磷的可用性的限制。尽管这种趋势可能会继续下去，但我们对这将如何影响淡水生态系统中二氧化碳和CH4的运动以及这些生态系统和大气之间的知识仍然不确定。利用我们最近发现的发现，P的可用性较低，似乎降低了两种蓝细菌（有时称为“蓝绿色藻类”）处理二氧化碳和甲烷营养（一组细菌）处理CH4的能力，我们提出n：p不平衡如何影响淡水微生物社区和淡淡的绿化房屋气体的淡水释放淡水释放淡水的淡水和温室气体的生产。对全球气候变化具有重大影响的影响。