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

淡水仅占地球表面的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，随后允许一些物种扩大其地理范围，同时驱动其他物种的范围收缩。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上限和下限。这项研究将沿着阿巴拉契亚山脉南部的一条海拔连续流进行，阿巴拉契亚山脉是生物多样性的热点，拥有独特的鱼类，这些鱼类对维持人类所依赖的健康淡水生态系统至关重要。该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。新的计算技术将被用来整合这些实验室实验的数据与野生鱼类种群的2年实地研究，以创建在21世纪世纪剩余时间的海拔变化的详细地图。在整个项目中，研究团队将与保护从业人员举办研讨会，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。一个专业的发展研讨会将在诺克斯维尔，田纳西州的K-12教师主办，实验室实验将在圣安东尼奥，得克萨斯州的西班牙裔服务机构进行，从而推进多样性，公平和包容性的STEM教育的社会目标。该项目将开发下一代物种分布模型（SDM）通过整合生物体水平的生物能量预算与社区水平的捕食者-猎物的相互作用。其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个同步环境因素如何驱动地理范围限制的理解。本研究将检验以下假设：（1）物种的海拔极限与能量从盈余到亏缺的过渡是一致的，这一过渡是沿海拔梯度沿着进行的。(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体能量收支的海拔差异的相对影响。这一新一代可持续发展机制框架将使用物种比较方法加以验证，重点是低海拔和高海拔的中上层（水柱）小鱼和底栖（河底）镖鲈。一旦得到验证，SDMS将根据未来的温度、水流和猎物丰度情况进行预测，以预测物种海拔和纬度限制的变化。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，逆梯度变化）将被用来探讨如何热生态位的演变可能会削弱未来的变化，在物种的范围限制。更一般地说，项目的发现将通过明确整合格林内利和埃尔顿生态位概念来阐明潜在的机制，从而促进对物种范围限制的理解。该奖项反映了NSF的法定使命，并被认为值得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来支持。

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.