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.

气候极端越来越超过生物体的生理阈值，限制了物种分布并最终导致栖息地丧失。对这些变化的韧性取决于环境特征，行为和生理学之间的相互作用，使物种能够进入合适的微气候。生态系统工程师是通过创建诸如洞穴之类的结构来修改环境的物种，这些结构可以提供更稳定的温度和湿度，从而使乘员缓冲乘员防止极端温度。这些生物的行为不仅对自己的持久性很重要，而且使其他物种能够进入合适的微气候。 Mojave Desert Tortoise是一位生态系统工程师，为避难所和筑巢而创建洞穴，并因气候变化而受到灭绝的威胁。最年轻的乌龟寿命阶段 - 鸡蛋，幼体和少年 - 由于其尺寸较小和修改环境的能力有限，因此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或小型哺乳动物洞穴来保护。该项目旨在了解沙漠乌龟如何通过洞穴创造来修改其环境，以表征如何通过洞穴使用来实现温度调节，并衡量洞穴的有效性，以防止在整个生命阶段进行温度升高，并特别强调筑巢的女性和早期生活阶段。这项研究将提供有关每个生命阶段对极端气候的弹性的新数据，并将在未来气候场景下为生命阶段的物种分布模型提供信息，从而确定可能成为气候避难所的地点。这项工作将开发特定年级的教育模块和课堂套件，以整合活跃的沙漠乌龟保护研究，并将在当地教室中实施这些模块。该项目还将为K-12教师，本科生，研究生和博士后学员提供培训机会。该项目是通过涉及环境生物学和综合有机系统和Paul G. Allen家族基金会的分层的联合计划来支持的。这项研究采用了一种机械方法来评估行为和生理灵活性在确定气候变化对气候变化对气候变化的韧性的作用，以使濒临灭绝的Mojave沙漠乌龟在整个生命阶段，重要的生态型生态系统。该研究旨在表征卵的温度敏感性和母体筑巢行为。测试温度和水力状况对少年洞穴使用，洞穴形态和体温的影响；量化野生乌龟中跨年龄阶层的行为和洞穴的热缓冲能力；并使用呼吸测定法来表征温度对能量消耗，水分流失和热偏好的影响。这些研究将为生命阶段特定的机械性利基模型（MNM）提供对改变气候的反应的关键生理参数，以确定将持续到未来的沙漠乌龟的最佳栖息地。最后，这项研究将通过从模型选择的站点收集环境数据来测试MNM预测。通过确定气候避难和核心保护区，这些模型将为未来的焦点地点提供莫哈韦沙漠乌龟的恢复活动，包括恢复和辅助移民。更广泛地说，结果将与使用洞穴的扩展物种和相关生物相关，并导致改进的经验和建模方法预测气候变化对这一多样化的生物体的影响。这项奖项反映了NSF的法定任务，并通过评估基金会的智力效果，并通过评估了基金会的范围。