Individual specialization and the trophic niche of aquatic consumers

水产消费者的个体专业化和营养生态位

• 批准号: RGPIN-2015-06677
• 负责人: Johnston, Thomas
• 金额: $ 1.53万
• 依托单位: Laurentian University of Sudbury
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=678296
• 关键词: Individual; specialization; trophic; niche; aquatic

Animals obtain their energy and nutrients from eating other organisms, and in turn, may themselves become food for other consumers. The study of these feeding relationships is called trophic ecology, and the network of feeding relationships in an ecosystem is called a food web. A species' functional role in an ecosystem is called its niche, and is defined by the resources it uses, both habitat and food. The trophic niche is that part of the niche defining what the species eats. Positions and dimensions of trophic niches of species in an ecosystem, as well their abundances, define the ecosystem food web structure. This structure affects energy and material flows, and the quantity and quality of foods ultimately available to us. Research on the trophic niche helps us to understand food web structure, as well as ecological and evolutionary processes.******The trophic niche of a species can be thought of as a space defined by the types and relative abundances of foods eaten. Species that eat a diversity of food types are said to occupy a large trophic niche. Populations are composed of individuals that differ from each other in various ways, including their trophic ecologies. A fascinating finding of recent research is that many species exhibit strong individual trophic specialization. That is, even though the trophic niche of the population may be large, individuals each tend to focus their feeding on a smaller, particular subset of food types. This phenomenon is very interesting to evolutionary ecologists because it may reflect the early stages of differentiation that eventually leads to speciation. My research program examines the trophic ecology of aquatic organisms using individual specialization as an index of trophic niche size.******A variety of techniques are used to measure the trophic niche. My research program will primarily use ecological tracers, in particular stable isotopes. These are measures of the chemical composition of an organism that reflect long-term dietary patterns. I will use ecological tracer data along with recently developed data analyses methods to estimate the trophic niche sizes of fish populations, and examine how they vary with respect to environmental conditions in lakes and rivers of the boreal shield ecoregion. I will also conduct laboratory experiments to test key assumptions about how ecological tracer data can be used and interpreted.******This research will help us to understand how the environment influences the specialization and diversification processes in animal populations, and how this influences the numbers and types of species that can co-exist. It will also help us understand how freshwater food webs function and may be altered by human activities, and this will improve our management of these aquatic systems. Finally, my laboratory experiments will allow us to refine how we use ecological tracers, and will broaden their application in ecological and environmental research.

动物通过食用其他生物体获得能量和营养，反过来，它们本身也可能成为其他消费者的食物。 对这些摄食关系的研究称为营养生态学，生态系统中的摄食关系网络称为食物网。 物种在生态系统中的功能作用称为其生态位，由其使用的资源（包括栖息地和食物）定义。 营养生态位是生态位中定义物种吃什么的部分。 生态系统中物种营养位的位置和规模及其丰度决定了生态系统的食物网结构。 这种结构影响能量和物质的流动，以及我们最终获得的食物的数量和质量。 对营养生态位的研究有助于我们了解食物网结构以及生态和进化过程。******一个物种的营养生态位可以被认为是由所吃食物的类型和相对丰度定义的空间。 据说，吃多种食物的物种占据了很大的营养生态位。 种群由在各种方面（包括营养生态）彼此不同的个体组成。 最近研究的一个令人着迷的发现是，许多物种表现出强烈的个体营养专门化。 也就是说，尽管种群的营养生态位可能很大，但每个个体都倾向于将其食物集中在较小的特定食物类型子集上。 这种现象对进化生态学家来说非常有趣，因为它可能反映了最终导致物种形成的分化的早期阶段。 我的研究项目使用个体特化作为营养生态位大小的指标来研究水生生物的营养生态学。******使用多种技术来测量营养生态位。 我的研究计划将主要使用生态示踪剂，特别是稳定同位素。 这些是反映长期饮食模式的生物体化学成分的测量值。我将使用生态示踪数据以及最近开发的数据分析方法来估计鱼类种群的营养生态位大小，并研究它们如何随着北方盾构生态区湖泊和河流的环境条件而变化。 我还将进行实验室实验，以测试有关如何使用和解释生态示踪数据的关键假设。******这项研究将帮助我们了解环境如何影响动物种群的专业化和多样化过程，以及这如何影响可以共存的物种的数量和类型。 它还将帮助我们了解淡水食物网如何发挥作用以及人类活动可能改变的方式，这将改善我们对这些水生系统的管理。 最后，我的实验室实验将使我们能够改进生态示踪剂的使用方式，并扩大其在生态和环境研究中的应用。