CAREER: Resolving multi-scale ecological consequences of thermal refuges amidst climate warming

随着时间的推移，地球上的大多数生命都会经历环境条件的变化，并且存在于不同空间的环境中。生态学领域试图解决的一个重大挑战是理解这种变化所产生的生物学后果。该项目将探讨一种重要的环境空间变化类型——热避难所的重要性。热避难所是生物在极端天气期间可能发现有益的地方，因为它们不像周围地区那样极端，并且可以在极端高温期间保持生物多样性。通过对淡水生态系统的实验和观察，该项目将研究生物如何利用热避难所，以及避难所的存在或不存在如何改变生物的组成及其特征。此外，这项研究将进行实验，以了解热避难所可能允许个体生物在热应力期间持续存在的条件。该项目将在一所主要面向本科生的机构进行，并将帮助提供信息，并作为侧重于环境变化后果的以探究为基础的本科生生态学课程的一部分完成。虽然热避难所通过尽量减少对致命条件的暴露而促进分类多样性的能力经常受到称赞，但其人口效益往往是假设的，而不是经验衡量的，正如避难所利用的人口水平成本以及避难所可能影响生态结果的环境变化的空间尺度和领域一样。这项研究将发展对热避难所在气候变暖中种群持续存在的作用的机制理解，以及它们的局限性。它的目的是1)记录热避难所的范围、利用和与之相关的多样性模式；2)评估和概括热应激下人口水平的成本和收益，以及3)了解热避难所如何改变极端温度事件下人口的持久性和动态。这些信息对于完善灭绝风险的估计是有价值的，因为它侧重于阐明在人口和群落动态展开的空间相关尺度上环境条件的影响。特别是，这项研究有可能帮助确定平均气温上升和偶发性事件的早期预警指标。拟议的活动将解决关于气候变暖中生物多样性命运的紧迫社会问题，并代表了通过维护、保存或设计热避难所的特征来促进预期的生态后果，从而减轻灾害的重要的第一步。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。

Most life on Earth experiences changes in environmental conditions over time and exists in environments that vary across space. One grand challenge the field of ecology seeks to address is understanding the resulting biological consequences of this variation. This project will address the significance of one important type of spatial variation in the environment, thermal refuges. Thermal refuges are locations organisms may find beneficial during periods of extreme weather in that they are not as extreme as surrounding locations, and may maintain biodiversity amidst periods of extreme heat. Using both experiments and observations in freshwater ecosystems to document how common thermal refuges are, the project will investigate how organisms use thermal refuges, and how the presence or absence of refuges can alter the composition of organisms and their traits. Additionally, this research will perform experiments to understand the conditions over which thermal refuges may allow individual organisms to persist during periods of thermal stress. The project will be conducted at a primarily-undergraduate institution, and will help inform, and be completed as part of, an undergraduate inquiry-based ecology course focused on the consequences of environmental variation.While often lauded for their capacity to promote taxonomic diversity by minimizing exposure to lethal conditions, the demographic benefits of thermal refuges are more often assumed than empirically measured, as are the population-level costs of refuge utilization, and spatial scales and domains of environmental variation over which refuges may influence ecological outcomes. This research will develop a mechanistic understanding of the role of thermal refuges for the persistence of populations amidst climate warming, as well their limitations. It aims to 1) document the extent of, utilization of, and patterns of diversity associated with, thermal refuges; 2) assess and generalize population-level costs and benefits of thermal refuges amidst thermal stress, and 3) understand how thermal refuges alter population persistence and dynamics in response to extreme temperature events. Such information is valuable for refining estimates of extinction risk as it focuses on elucidating the impact of environmental conditions at the spatially relevant scales over which population and community dynamics unfold. In particular, this research has the potential to help identify early warning indicators amidst rising mean temperatures and episodic events. The proposed activities will address the pressing societal concern regarding the fate of biodiversity amidst climate warming, and represents an important initial step in a path towards disaster mitigation by maintaining, preserving, or engineering features of thermal refuges that promote desired ecological consequences.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.