Changing environmental conditions in Signy Island and McMurdo Dry Valleys and its impact on diatoms in lake microbial mats

西格尼岛和麦克默多干谷环境条件的变化及其对湖泊微生物垫中硅藻的影响

• 批准号: 2705839
• 金额: --
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 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=studentship-2705839
• 关键词: Changing; environmental; conditions; Signy; Island

Antarctica has entered a period of rapid climate and environmental change which is largely impacting the functioning and productivity of the limnetic ecosystem. One of the most prominent features of most limnetic ecosystems are the extensive microbial mats that dominate primary production across Antarctica. Microbial mats are horizontally and vertically stratified microbial communities that are structured by a physiochemical gradient within the environments. In polar regions climate-related variables such as turbidity, salinity, and nutrient concentration and temperature are the most critical variables structuring the benthic microbial community. The photosynthetic mats in Antarctic lakes are dominated by filamentous cyanobacteria which form a matrix which harbours organisms with a lower tolerance for harsh conditions such diatoms. The diatoms within these microbial mats are particularly responsive to a change in environmental variables and therefore, can be useful indicators of the rapid environmental change that is occurring across Antarctica. In this project, we will use genetic data, diatom taxonomy and morphology to better understand impacts of climate and nutrient enrichment in freshwater systems of Signy Island The project would be in two parts to understand both short-term impacts and long-term impacts of the changing environmental variables on diatom communities using (1) modern microbial mat samples from 2016 and 1990 (2) sedimentary lake core samples.. A combination of ancient sedimentary DNA (aDNA) and morpho- species identification to identify diatom composition in lakes of Signy Island and Dry Valleys across both time and space, which can then be related to environmental variables such as temperature change and precipitation. The project will also explore environmental factors driving phenotypic plasticity in diatoms by studying morphological changes in diatom species in both modern and core samples. Studying the morphology of diatoms can reveal other intricate details of the rapid environmental change that is occurring across Antarctica. Using a both morphology and genetic data on present and ancient DNA would allow us to assess how increasing temperatures and meltwater with future climate change will affect diatom diversity and functioning in Antarctic freshwater ecosystems and contribute to environmental monitoring.

南极洲已进入气候和环境快速变化的时期，这在很大程度上影响了湖沼生态系统的功能和生产力。大多数湖沼生态系统最显着的特征之一是广泛的微生物垫，它们在整个南极洲的初级生产中占主导地位。微生物垫是水平和垂直分层的微生物群落，由环境内的理化梯度构成。在极地地区，与气候相关的变量，如浊度、盐度、营养物浓度和温度，是构成底栖微生物群落的最关键变量。南极湖泊中的光合垫以丝状蓝藻为主，它们形成一个基质，其中含有对恶劣条件耐受性较低的生物体，例如硅藻。这些微生物垫中的硅藻对环境变量的变化特别敏感，因此可以作为整个南极洲正在发生的快速环境变化的有用指标。在这个项目中，我们将利用遗传数据、硅藻分类学和形态学来更好地了解气候和营养富集对西格尼岛淡水系统的影响。该项目将分为两部分，以了解气候变化的短期影响和长期影响使用 (1) 2016 年和 1990 年的现代微生物垫样本 (2) 沉积湖核心样本改变硅藻群落的环境变量。结合古代沉积 DNA (aDNA) 和形态物种识别来识别西格尼岛和干谷湖泊中不同时间和空间的硅藻成分，然后可以与温度变化和降水等环境变量相关。该项目还将通过研究现代和核心样本中硅藻物种的形态变化来探索驱动硅藻表型可塑性的环境因素。研究硅藻的形态可以揭示整个南极洲正在发生的快速环境变化的其他复杂细节。利用现在和古代 DNA 的形态和遗传数据，我们可以评估未来气候变化导致的气温和融水增加将如何影响南极淡水生态系统的硅藻多样性和功能，并有助于环境监测。