Habitat effects on stream productive capacity, energy flow, and adaptive tradeoffs among juvenile salmonids

栖息地对河流生产力、能量流和幼鲑鱼适应性权衡的影响

• 批准号: RGPIN-2016-04250
• 负责人: Rosenfeld, Jordan
• 金额: $ 2.04万
• 依托单位: University of British Columbia
• 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=682408
• 关键词: Habitat; effects; stream; productive; capacity

The ability of fish to successfully exploit stream habitats depends on physical habitat structure, prey production, and the abundance of predators and competitors. These features form the adaptive landscape for drift-feeding fish like salmon and trout, while simultaneously constraining energy transfer to the fish trophic level. Along with water chemistry and temperature, physical habitat structure (e.g. channel form, velocity, substrate) remains the most fundamental determinant of stream productive capacity, and understanding physical constraints on fish production is key to predicting the effects of habitat change on fish populations.*** The objectives of this proposal are i) to develop a general process model relating production of invertebrate drift and juvenile drift-feeding salmonids (i.e. Pacific salmon and trout) to stream habitat structure and discharge, as a quantitative framework for modeling habitat and flow effects on juvenile salmonid production in streams; ii) to experimentally determine the adaptive tradeoffs differentiating juvenile salmonids at different taxonomic levels, with a particular emphasis on understanding the role of growth differentiation; and iii) to evaluate whether latitudinal constraints on herbivorous fish distribution affect energy flow and production of other functional feeding groups of fish, particularly drift-feeding fish (e.g., juvenile salmonids).*** This research will provide i) a novel synthesis of habitat effects on production and modeling of invertebrate drift and juvenile salmonid carrying capacity; ii) significant advances in instream flow science, both in terms of model development, validation, and identification of empirical flow thresholds; iii) improved understanding of the physiological basis of adaptive tradeoffs that allow habitat partitioning and co-existence along environmental gradients; and iv) an assessment of the generality, underlying causation, and consequences of large-scale latitudinal clines in stream (herbivore) trophic structure. These represent important contributions to fundamental issues in stream, organismal, and community ecology, and will provide direct application to improving management of endangered fish species, instream flows, and habitat restoration in Canada, with potential impacts ranging from local (endangered species) to global (improved instream flow modeling techniques).**

鱼类成功开发溪流栖息地的能力取决于自然栖息地结构、猎物产量以及捕食者和竞争对手的丰度。这些特征形成了鲑鱼和鲑鱼等漂流摄食性鱼类的适应环境，同时限制了能量转移到鱼类营养水平。除了水化学和温度，物理栖息地结构(如河道形状、流速、底物)仍然是河流生产能力的最基本决定因素，了解对鱼类生产的物理限制是预测栖息地变化对鱼类种群影响的关键。*本建议的目标是：i)开发一个关于无脊椎动物漂流和幼年漂流摄食性鲑鱼(即太平洋鲑鱼和鲑鱼)的生产到溪流栖息地结构和排放的一般过程模型，作为模拟栖息地和水流对溪流中幼鲑鱼生产的影响的量化框架；Ii)在实验上确定在不同分类水平上区分幼鲑鱼的适应性权衡，特别强调了解生长分化的作用；以及iii)评估草食性鱼类分布的纬度限制是否影响其他功能性摄食性鱼类，特别是漂流性鱼类(例如幼鲑鱼)的能量流动和产量。*这项研究将提供一种新的综合生境对无脊椎动物漂流和幼鲑鱼载量的生产和建模的影响；ii)在河流径流科学方面的重大进展，无论是在模型开发、验证和经验流量阈值的确定方面；(Iii)更好地理解适应性权衡的生理基础，这种权衡允许栖息地划分和沿环境梯度共存；以及(Iv)对溪流(食草动物)营养结构中大规模纬度斜坡的一般性、潜在原因和后果进行评估。这些是对河流、生物和群落生态学基本问题的重要贡献，并将直接应用于改善加拿大濒危鱼类物种的管理、河流径流和栖息地恢复，潜在影响范围从当地(濒危物种)到全球(改进的河流水流模拟技术)。