Climate control of aquatic microbial ecosystems

水生微生物生态系统的气候控制

• 批准号: RGPIN-2014-05665
• 负责人: Vincent, Warwick
• 金额: $ 6.12万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=667816
• 关键词: Climate; control; aquatic; microbial; ecosystems

Global climate models predict that the greatest warming effects of greenhouse gas accumulation in the atmosphere will be at the highest latitudes of the Arctic, and consistent with these projections, the High Arctic appears to be warming at rates well above the global mean. Over the last 15 years, we have established an observatory at Ward Hunt Island, at the northern limit of the Canadian High Arctic coastline. This has proven to be a strategic research site for the detection and analysis of environmental change given the diversity of freshwater and marine ecosystems, their extreme sensitivity to perturbations of the cryosphere (snow and ice-containing environments), and the current trend of accelerated warming at this far northern latitude (83 degrees North, 1018 km north of Resolute Bay, 172 km northwest of Alert). For this next phase of my Discovery Grant program, we will focus our research on the Ward Hunt region via a coordinated set of graduate student and postdoctoral projects, to address key questions and hypotheses about aquatic habitats, communities and processes in the warming Arctic.**Microscopic life underpins the biological production, food web processes, nutrient fluxes and biodiversity of polar ecosystems. Our research program will focus on achieving an improved understanding of this microbial world in the lakes, wetlands, streams and fjords along the coast of northern Ellesmere Island, within helicopter range of our base camp and laboratory at Ward Hunt Island. Three themes will be addressed, building on our studies to date. Firstly, we will apply advanced microbiological and molecular (DNA and RNA sequencing) methods to evaluate the network relationships among the microbial plankton populations in these waters, and the changes in microbial community structure and function across salinity gradients, including in newly emergent ecosystems that were previously constrained by thick ice. Secondly, we will address the striking dichotomy in the distribution of minute photosynthetic plankton (cells less than 3 micrometres in diameter, termed picophytoplankton) in which the dominant cell types are picocyanobacteria in lakes and picoeukaryotes in the sea. This research will include observations, cultures and controlled experiments to evaluate the food web effects on these populations relative to their temperature-dependent growth rates. Thirdly, we will continue our work on the thick biofilm communities that coat the base of shallow freshwaters (cyanobacterial mats) by way of culture experiments and molecular analyses to determine how these major constituents of northern ecosystems are functionally organized, the coupling between photosynthetic and non-photosynthetic constituents of the communities, and their responses to environmental change. The projects in these three themes will apply diverse approaches including emerging new molecular and cytometric methods and will address topics at the leading edge of microbial ecology. The results will improve our ability to monitor and predict the responses of northern ecosystems to ongoing environmental change.**The originality of this work lies in our proven ability to achieve new insights into microbial ecosystems at this most remote and strategic part of Canada, to place this work in a broad global as well as ecological context, and to report our observations of ecosystem change in this northernmost region to Canadians (including northerners) and to the rest of the world. Our research directly addresses Canada's environmental needs and international responsibilities in polar research and reporting, and the results are likely to continue to attract wide public, policy maker and scientific interest.

全球气候模型预测，大气中温室气体积累的最大变暖影响将发生在北极的最高纬度，与这些预测一致，高北极地区的变暖速度似乎远远高于全球平均水平。在过去的15年里，我们在加拿大北极高地海岸线北端的沃德亨特岛建立了一个天文台。鉴于淡水和海洋生态系统的多样性，它们对冰冻圈(含雪和含冰环境)的扰动极其敏感，以及目前这一极北纬地区(北纬83度，索洛特湾以北1018公里，阿勒特西北172公里)变暖的趋势，这已被证明是一个探测和分析环境变化的战略研究地点。在我的发现资助计划的下一阶段，我们将通过一系列协调的研究生和博士后项目，将我们的研究重点放在沃德亨特地区，以解决关于北极变暖的水生栖息地、群落和过程的关键问题和假设。**微生物支撑着极地生态系统的生物生产、食物网络过程、营养通量和生物多样性。我们的研究计划将专注于在埃尔斯米尔岛北部海岸的湖泊、湿地、溪流和峡湾实现对这个微生物世界的更好理解，在我们位于沃德亨特岛的大本营和实验室的直升机覆盖范围内。在我们迄今研究的基础上，将讨论三个主题。首先，我们将应用先进的微生物学和分子(DNA和RNA测序)方法来评估这些水域中浮游微生物种群之间的网络关系，以及跨盐度梯度的微生物群落结构和功能的变化，包括以前受到厚冰限制的新出现的生态系统。其次，我们将解决微小光合作用浮游生物(直径小于3微米的细胞，称为微藻浮游植物)分布的显著二分法，其中主要细胞类型是湖泊中的微蓝细菌和海洋中的微真核生物。这项研究将包括观察、培养和对照实验，以评估食物网对这些种群的影响，相对于它们依赖温度的增长率。第三，我们将继续通过培养实验和分子分析的方式，对覆盖在浅水淡水(蓝藻垫子)底部的厚厚的生物膜群落进行研究，以确定北方生态系统的这些主要组成部分是如何功能组织的，群落的光合作用和非光合作用成分之间的耦合，以及它们对环境变化的响应。这三个主题的项目将采用不同的方法，包括新出现的分子和细胞计量学方法，并将处理微生物生态学前沿的主题。结果将提高我们监测和预测北方生态系统对持续环境变化的反应的能力。**这项工作的原创性在于我们被证明有能力对加拿大这一最偏远和最具战略意义的地区的微生物生态系统获得新的见解，将这项工作置于广泛的全球和生态背景下，并向加拿大人(包括北方人)和世界其他地区报告我们对这一最北端地区生态系统变化的观察。我们的研究直接解决了加拿大在极地研究和报告方面的环境需求和国际责任，其结果可能会继续吸引广泛的公众、政策制定者和科学兴趣。