"Life under the ice" - winter ecology of temperate rivers

“冰下的生命”——温带河流冬季生态

• 批准号: RGPIN-2019-04783
• 负责人: Hayden, Brian
• 金额: $ 2.04万
• 依托单位: University of New Brunswick
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=761625
• 关键词: Life; under; ice; winter; ecology

Aquatic environments in Canada are exposed to extreme seasonal variation in temperature, productivity and food availability. Surprisingly however, our understanding of the ecological function of river ecosystems is overwhelmingly derived from studies conducted during the ice-free months and remarkably little of known regarding how these ecosystems function during winter. Hence, as periods of winter ice cover become shorter we lack the fundamental knowledge to determine what component of ecosystem function is being lost and how to mitigate these effects. Over the next 5 years, I will conduct a field-based research program to a) determine winter ecology of river communities, characterising the food web structure and ecosystem function of ice-covered rivers and b) assess how climate change may modify these interactions and influence ecosystem function. In Objective 1, MSc1, 2, 3 and I will conduct seasonal (fall, winter and spring) sampling in rivers in New Brunswick to assess seasonal variation in the community structure and function of river communities. MSc1 and I will use stable isotope analysis, chromatography, microscopy and DNA analysis to assess seasonal variation the community structure and nutritional quality of biofilm, the base of temperate river food webs. MSc2 and I will use quantitative ecology and stable isotope analysis to determine seasonal variation in the community structure and resource use of invertebrate communities. MSc3 and I will use diet and stable isotope analysis to assess the trophic ecology and energy pathways supporting fish communities in ice covered rivers. In Objective 2, PhD1 and I will employ the methods developed in Objective 1 in eight New Brunswick rivers spanning a latitudinal gradient equating to a 2°C range in mean annual temperature and including four groundwater fed rivers which remain ice free during winter months. We will conduct seasonal sampling of primary producers, aquatic invertebrates and fishes at each site and use a combination of stable isotope analysis, fatty acid analysis and quantitative ecology to identify how variation in length and intensity of winter influences the structure and function of temperate river food webs. This program will train 4 graduate and 9 undergraduate HQP and will provide a unique insight into seasonal variation in river ecosystem function. This work will advance the field of ecology by developing a novel characterization of the links between structure and function of aquatic communities which incorporates seasonal changes in the river environment. In addition, it will provide a better method to predict the effect of climate change on riverine communities and establish a model which can be applied to temperate rivers across Canada.

加拿大的水生环境受到温度、生产力和食物供应的极端季节性变化的影响。然而，令人惊讶的是，我们对河流生态系统的生态功能的理解绝大多数来自于在无冰月份进行的研究，而对这些生态系统在冬季的功能知之甚少。因此，随着冬季冰层覆盖期的缩短，我们缺乏基本的知识来确定生态系统功能的哪些组成部分正在丧失，以及如何减轻这些影响。在接下来的5年里，我将开展一项基于实地的研究计划，以a)确定河流群落的冬季生态，表征冰覆盖河流的食物网结构和生态系统功能；b)评估气候变化如何改变这些相互作用并影响生态系统功能。在目标1中，MSc1、2、3和我将在新不伦瑞克省的河流中进行季节性（秋、冬、春）采样，以评估河流群落结构和功能的季节性变化。MSc1和我将使用稳定同位素分析、色谱、显微镜和DNA分析来评估温带河流食物网基础生物膜的群落结构和营养质量的季节变化。MSc2和我将使用定量生态学和稳定同位素分析来确定无脊椎动物群落结构和资源利用的季节变化。MSc3和我将使用饮食和稳定同位素分析来评估冰覆盖河流中支持鱼类群落的营养生态和能量途径。在目标2中，PhD1和我将在8条新不伦瑞克省河流中采用目标1中开发的方法，这些河流跨越的纬度梯度相当于年平均温度2°C的范围，其中包括4条在冬季保持无冰的地下水河流。我们将在每个站点对初级生产者、水生无脊椎动物和鱼类进行季节性采样，并结合稳定同位素分析、脂肪酸分析和定量生态学来确定冬季长度和强度的变化如何影响温带河流食物网的结构和功能。该项目将培养4名研究生和9名本科生，并将对河流生态系统功能的季节变化提供独特的见解。这项工作将通过发展水生群落结构和功能之间联系的新特征来推进生态学领域，其中包括河流环境的季节性变化。此外，它将为预测气候变化对河流社区的影响提供更好的方法，并建立一个可应用于加拿大温带河流的模型。