Ecological effects of glacial dust deposition on remote Arctic lakes

冰川尘埃沉积对北极偏远湖泊的生态影响

• 批准号: NE/P011578/1
• 负责人: Nicholas Anderson
• 金额: $ 65.4万
• 依托单位: Loughborough University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FP011578%2F1
• 关键词: Ecological; effects; glacial; dust; deposition

The Arctic is changing rapidly as a result of climate warming and other global environmental change processes. One of the most obvious effects of altered Arctic heat budgets is the thinning of the Greenland ice sheet and the retreat of outlet glaciers. However, the increased fluvio-glacial output from glaciers is also laden with silt and there is growing evidence that such output from the Greenland ice sheet is increasing with enhanced seasonal melting. Some of this glacially-derived material is lost to the marine system but a significant part is deposited on glacial outwash plains from where the finer particles are deflated and transported to nearby terrestrial and aquatic ecosystems. Importantly this silt and the deflated dust is not inert. Because of its high nutrient content (carbon, phosphorus, nitrogen, silica and micronutrients), this silt/dust may be ecologically important because of the low nutrient status of adjacent aquatic and terrestrial ecosystems. There is now considerable evidence that dust stimulates microbiological activity on glacial ice and in cryoconite holes (meltwater holes caused by particle deposition which increases heat uptake) on the ice surface. However, there are no comparable studies on how glacially-derived dust influences lakes within terrestrial areas adjacent to the ice margin, despite the knowledge that lakes are hotspots of carbon processing.The vast majority of lakes adjacent to the Greenland ice sheet are not hydrologically connected to it by meltwater channels, and so aerially-delivered dust might be an important or even predominant lake nutrient source. Fertilization of lakes by nutrients associated with dust stimulates primary production and hence carbon dynamics. Dust inputs to lakes at lower latitudes is known to have major impacts on lake biogeochemical cycling. There has, however, been limited consideration of these processes in the Arctic where lakes are important for regional carbon cycling although they are not well integrated into regional and global carbon budgets. Arctic lakes are numerous (their abundance is highest between 65-75 degrees N) and generally very nutrient poor and if dust increases lake productivity as an indirect effect of changing climate, this will be a positive result. This is due to the disproportional effect on increased carbon burial which removes carbon from the terrestrial carbon cycle and hence can offset warming. Conversely, increasing organic matter input to aquatic ecosystems may enhance microbial decomposition in lakes and stimulate lake CO2 emissions. In this study we will compare the ecological effects of glacially-derived dust on lakes along a gradient of dust deposition rates in SW Greenland and assess its role in regional carbon and aquatic community dynamics at a range of temporal (annual to centennial) and spatial scales (lake to regional landscape).

由于气候变暖和其他全球环境变化过程，北极正在迅速变化。北极热量收支变化最明显的影响之一是格陵兰冰盖变薄和出口冰川退缩。然而，冰川产生的越来越多的河流-冰川输出也充满了淤泥，越来越多的证据表明，格陵兰冰盖的这种输出正在随着季节性融化的加剧而增加。这些来自冰川的物质中有一部分流失到海洋系统中，但很大一部分沉积在冰川外冲平原上，在那里，较细的颗粒被压缩并输送到附近的陆地和水生生态系统。重要的是，这些淤泥和泄气的灰尘不是惰性的。由于其高营养成分（碳、磷、氮、二氧化硅和微量营养素），由于邻近的水生和陆地生态系统的营养状况较低，这种淤泥/粉尘可能具有重要的生态意义。现在有相当多的证据表明，灰尘刺激冰川冰和冰表面的冰孔（由颗粒沉积引起的融水孔，增加了热量吸收）中的微生物活动。然而，尽管人们知道湖泊是碳加工的热点，但目前还没有关于冰川产生的灰尘如何影响冰缘附近陆地区域内湖泊的可比研究。与格陵兰冰原相邻的绝大多数湖泊在水文上并没有通过融水通道与之相连，因此空中输送的灰尘可能是一个重要的甚至是主要的湖泊营养源。与粉尘有关的营养物对湖泊的施肥刺激了初级生产，从而促进了碳动态。低纬度地区湖泊的粉尘输入对湖泊生物地球化学循环具有重要影响。然而，对北极地区这些过程的考虑有限，因为北极地区的湖泊对区域碳循环很重要，尽管它们没有很好地纳入区域和全球碳预算。北极的湖泊数量众多（北纬65-75度之间的湖泊数量最多），通常营养贫乏，如果沙尘作为气候变化的间接影响增加了湖泊的生产力，这将是一个积极的结果。这是由于增加的碳埋藏造成的不成比例的影响，它将碳从陆地碳循环中移除，从而可以抵消变暖。相反，增加对水生生态系统的有机物输入可能会促进湖泊微生物分解并刺激湖泊二氧化碳排放。在这项研究中，我们将沿着格陵兰岛西南部的沙尘沉积速率梯度比较冰川沙尘对湖泊的生态影响，并在时间（年至百年）和空间尺度（湖泊到区域景观）上评估其在区域碳和水生群落动态中的作用。

项目成果

Exploring the effects of glacially-derived dust on lake ecosystems in southwestern Greenland

探索冰川产生的尘埃对格陵兰岛西南部湖泊生态系统的影响

• 发表时间: 2019
• 作者: Prater C

Effects of locally-derived dust deposition on low nutrient lakes in West Greenland

当地尘埃沉降对西格陵兰低营养盐湖的影响

• 发表时间: 2017
• 作者: Prater C.

The importance of aeolian dust inputs into oligotrophic lakes in West Greenland

风尘输入西格陵兰贫营养湖泊的重要性

• 发表时间: 2018
• 作者: Joanna E. Bullard

Increases in primary production in response to aeolian dust deposition into Greenlandic lakes

因风尘沉积进入格陵兰湖而导致初级生产增加

• 发表时间: 2019
• 作者: Prater C

Landscape Controls on Nutrient Stoichiometry Regulate Lake Primary Production at the Margin of the Greenland Ice Sheet

景观对养分化学计量的控制调节格陵兰冰盖边缘的湖泊初级生产

• DOI: 10.1007/s10021-021-00693-x
• 发表时间: 2021
• 期刊: Ecosystems
• 影响因子: 3.7
• 作者: Prater C