Collaborative Research: Burrows as buffers: do microhabitat selection and behavior mediate desert tortoise resilience to climate change?

合作研究：洞穴作为缓冲区：微生境选择和行为是否会调节沙漠龟对气候变化的适应能力？

• 批准号: 2301677
• 负责人: Eric Riddell
• 金额: $ 32.64万
• 依托单位: Iowa State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-04-01 至 2023-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2301677&HistoricalAwards=false
• 关键词: Collaborative; Research; Burrows; buffers; do

Climate extremes increasingly exceed physiological thresholds for organisms, constraining species distributions and ultimately leading to habitat loss. Resilience to these changes depends on interactions between environmental features, behavior, and physiology that enable species to access suitable microclimates. Ecosystem engineers are species that modify their environment by creating structures, such as burrows, which can provide more stable temperature and humidity, buffering occupants against temperature extremes. The actions of these organisms are important not only for their own persistence but to enable other species to access suitable microclimates. The Mojave desert tortoise is an ecosystem engineer that creates burrows for shelter and nesting and is threatened with extinction, in part due to climate change. The youngest tortoise life stages - eggs, hatchlings, and juveniles - are particularly vulnerable to temperature extremes due to their small size and limited ability to modify their environment. These life stages rely on maternal nest placement or small mammal burrows for protection. This project aims to understand how desert tortoises modify their environment through burrow creation, to characterize how thermoregulation is achieved via burrow use, and to measure the effectiveness of burrows to buffer against rising temperature across life stages, with a particular emphasis on nesting females and early life stages. This research will provide new data on the resiliency of each life stage to climate extremes and will inform life stage-specific models of species distribution under future climate scenarios, identifying sites that may become climate refugia. This work will develop grade-specific educational modules and classroom kits that integrate active desert tortoise conservation research and will implement these modules in local classrooms. This project will also provide training opportunities for K-12 teachers, undergraduate students, a graduate student, and a post-doctoral trainee. This project is being supported via a joint program involving the Divisions of Environmental Biology and Integrative Organismal Systems and the Paul G. Allen Family Foundation.This research takes a mechanistic approach to evaluate the role of behavioral and physiological flexibility in determining resilience to climate change for the endangered Mojave desert tortoise across life stages, an important ecosystem engineer. The research seeks to characterize temperature sensitivity of eggs and maternal nesting behavior; test the effects of temperature and hydric status on juvenile burrow use, burrow morphology, and body temperature; quantify the thermal buffering capacity of behavior and burrows across age classes in wild tortoises; and use respirometry to characterize temperature effects on energy expenditure, water loss and thermal preference. These studies will provide key physiological parameters for life stage-specific mechanistic niche models (MNMs) of response to altered climate to identify optimal habitat for desert tortoises that will persist into the future. Finally, this research will test MNM predictions by collecting environmental data from model-selected sites. By identifying climate refugia and core conservation areas, these models will inform future focal sites for Mojave desert tortoise recovery activities, including restoration and assisted migration. More broadly, results will be relevant for the extended group of burrowing species and commensal organisms that use burrows, and lead to improved empirical and modelling methods for forecasting the impacts of climate change on this diverse group of organisms.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.

极端气候日益超出生物体的生理阈值，限制物种分布并最终导致栖息地丧失。对这些变化的适应能力取决于环境特征、行为和生理之间的相互作用，使物种能够获得合适的小气候。生态系统工程师是通过创造洞穴等结构来改变环境的物种，这些结构可以提供更稳定的温度和湿度，缓冲居住者免受极端温度的影响。这些生物体的行为不仅对于它们自身的持续存在很重要，而且对于使其他物种能够获得合适的小气候也很重要。莫哈韦沙漠龟是一种生态系统工程师，它为庇护和筑巢创造洞穴，但由于气候变化而面临灭绝的威胁。最年轻的陆龟生命阶段——卵、幼龟和幼龟——由于体型小且改变环境的能力有限，特别容易受到极端温度的影响。这些生命阶段依赖于母体巢穴的放置或小型哺乳动物洞穴的保护。该项目旨在了解沙漠龟如何通过创造洞穴来改变其环境，描述如何通过使用洞穴来实现体温调节，并测量洞穴在整个生命阶段缓冲温度上升的有效性，特别强调筑巢的雌性和早期的沙漠龟。人生阶段。这项研究将提供有关每个生命阶段对极端气候的适应能力的新数据，并将为未来气候情景下特定生命阶段的物种分布模型提供信息，确定可能成为气候避难所的地点。这项工作将开发针对特定年级的教育模块和课堂套件，整合积极的沙漠龟保护研究，并将在当地教室实施这些模块。该项目还将为 K-12 教师、本科生、研究生和博士后实习生提供培训机会。该项目得到了环境生物学和综合有机系统部门以及保罗·G·艾伦家庭基金会的联合计划的支持。这项研究采用机械方法来评估行为和生理灵活性在确定气候变化适应能力方面的作用。濒临灭绝的莫哈韦沙漠龟在各个生命阶段都是重要的生态系统工程师。该研究旨在表征鸡蛋的温度敏感性和母体筑巢行为；测试温度和水分状态对幼年洞穴使用、洞穴形态和体温的影响；量化野生陆龟不同年龄段的行为和洞穴的热缓冲能力；并使用呼吸测量法来表征温度对能量消耗、水分流失和热偏好的影响。这些研究将为响应气候变化的特定生命阶段的机械生态位模型（MNM）提供关键的生理参数，以确定沙漠龟未来持续存在的最佳栖息地。最后，这项研究将通过从模型选择的地点收集环境数据来测试 MNM 的预测。通过确定气候保护区和核心保护区，这些模型将为未来莫哈韦沙漠龟恢复活动的重点地点提供信息，包括恢复和辅助迁徙。更广泛地说，研究结果将与更多的穴居物种和使用洞穴的共生生物相关，并改进经验和建模方法，以预测气候变化对这一多样化生物群体的影响。该奖项反映了 NSF 的法定使命和通过使用基金会的智力价值和更广泛的影响审查标准进行评估，该项目被认为值得支持。