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）排放的主要来源，这两种气体是两种强大的温室气体。富氮肥料的使用及其由于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。这些关键的营养物质限制了藻类的生长，可用于支持水生野生动物的能量，以及全球范围内这一重要生态系统的温室气体排放。在过去的40年里，人类活动造成的氮径流的快速增长使磷的输入相形见绌，并使全球氮磷比的平衡从19：1转变为30：1，使越来越多的湖泊生态系统受到磷可用性的限制。虽然这一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内以及这些生态系统与大气之间的CO2和CH4运动的认识仍然不确定。利用我们最近的发现，低可用性的P似乎减少能力的蓝藻（有时称为“蓝绿藻”）处理CO2和甲烷氧化菌（一组细菌）处理CH4，我们建议揭示如何N：P的不平衡影响淡水微生物群落和淡水湖泊中的温室气体排放，对全球气候变化的影响。