Collaborative Research: ORCC: The role of bioenergetic budgets in defining elevation limits and modeling geographic ranges of species

淡水只占地球表面的0.8%，但这些生态系统却拥有全球31%的鱼类生物多样性。持续的气候变化正在改变鱼类的生理和行为，并随后允许一些物种扩大其地理范围，同时推动其他物种的范围缩小。该项目的目标是预测气候变化如何改变山涧和河流中鱼类的海拔高低界限。这项研究将沿着阿巴拉契亚山脉南部的一条海拔较高的河流连续体进行，这是一个生物多样性的热点，这里栖息着独特的鱼类，它们对维持人类赖以生存的健康淡水生态系统至关重要。研究小组将进行实验室实验，以测量温度对鱼类生理、行为和生长的影响。新的计算技术将用于将这些实验室实验的数据与为期两年的野生鱼类种群实地研究相结合，以创建21世纪剩余时间内海拔变化的详细地图。在整个项目中，研究小组将与保护从业者一起举办研讨会，将研究成果转化为现实世界的工具，可以立即为保护决策提供信息。将在田纳西州诺克斯维尔为K-12教师举办专业发展研讨会，并在德克萨斯州圣安东尼奥的西班牙裔服务机构进行实验室实验，从而推进STEM教育的多样性，公平性和包容性的社会目标。该项目将通过整合生物水平的生物能量预算和群落水平的捕食者-猎物相互作用来开发下一代物种分布模型（SDMs）。目标是提高对生理和行为特征以及与气候和土地利用变化相关的多种同时发生的环境因素如何驱动地理范围限制的理解。本文将对以下假设进行验证：(1)物种的海拔极限与沿海拔梯度从能量过剩到能量不足的转变是一致的。(2)物种的生理和行为特征决定了温度、水流和猎物丰度对生物能量收支海拔差异的相对影响。下一代SDM框架将使用物种比较方法进行验证，重点关注低海拔和高海拔的中上层（水柱）小鱼和底栖（河底）鱼类。一旦得到验证，SDMs将在未来温度、水流和猎物丰度的情景下进行预测，以预测物种海拔和纬度极限的变化。由于这些下一代sdm的输入是热反应规范，基于热适应理论的生态进化假设（例如，反梯度变化）将用于探索热生态位进化如何减弱物种范围限制的未来变化。更一般地说，项目发现将通过明确整合格林内尔和埃尔顿生态位概念来阐明潜在机制，从而促进对物种范围限制的理解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Freshwaters cover only 0.8% of Earth’s surface, yet these ecosystems harbor 31% of global fish biodiversity. Ongoing climate change is altering the physiology and behavior of fishes, and subsequently allowing some species to expand their geographic ranges while driving range retraction of other species. The goal of this project is to forecast how changing climate is shifting the lower and upper elevation limits of fishes in mountain streams and rivers. The research will take place along an elevational stream continuum in the southern Appalachian Mountains—a hotspot of biodiversity harboring unique fishes that are essential for maintaining healthy freshwater ecosystems on which humanity depends. The research team will perform laboratory experiments to measure the effect of temperature on fish physiology, behavior, and growth. New computational techniques will be used to integrate data from these laboratory experiments with a 2-year field study of wild fish populations to create detailed maps of elevational shifts during the remainder of the 21st century. Throughout the project, the research team will host workshops with conservation practitioners to transform research findings into real-world tools that can immediately inform conservation decisions. A professional development workshop will be hosted for K-12 teachers in Knoxville, TN, and laboratory experiments will take place at a Hispanic Serving Institution in San Antonio, TX, thus advancing societal goals of diversity, equity, and inclusion in STEM education.This project will develop the next generation of species distribution models (SDMs) by integrating organism-level bioenergetic budgets with community-level predator-prey interactions. The goal is to improve understanding of how physiological and behavioral traits as well as multiple, simultaneous environmental factors associated with climate and land use change drive geographic range limits. The following hypotheses will be tested: (1) Elevational limits of species are concordant with transitions from energy surplus to deficit along the elevation gradient. (2) Physiological and behavioral traits of species determine the relative effects of temperature, stream flow, and prey abundance on elevational differences in organismal energy budgets. This next-gen SDM framework will be validated using a species comparative approach, focusing on low- and high-elevation pairs of pelagic (water column) minnows and benthic (stream bottom) darters. Once validated, SDMs will be projected under future scenarios of temperature, stream flow, and prey abundance to forecast shifts in species elevational and latitudinal limits. Because the inputs for these next-gen SDMs are thermal reaction norms, eco-evolutionary hypotheses based in established theory of thermal adaptation (e.g., countergradient variation) will be used to explore how thermal niche evolution might attenuate future shifts in species range limits. More generally, project findings will advance understanding of species range limits by explicitly integrating Grinnellian and Eltonian niche concepts to elucidate underlying mechanisms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.