Doctoral Dissertation Research: Examining the effects of small mammal structures and population changes on biogeochemical cycling in Arctic soils

博士论文研究：研究小型哺乳动物结构和种群变化对北极土壤生物地球化学循环的影响

• 批准号: 2113432
• 负责人: Jennie McLaren
• 金额: $ 3.49万
• 依托单位: University of Texas at El Paso
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-15 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2113432&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Examining; effects

Arctic tundra covers approximately 6% of the earth's land surface yet stores 25% of the world’s soil carbon. As the climate warms, this stored carbon is released to the atmosphere, further enhancing climate warming; properly modeling this feedback requires information on what controls the carbon cycle in Arctic soils. To date, most studies of the Arctic carbon cycle have neglected the possible roles played by Arctic animals in controlling soil biogeochemical cycles. One important way that animals may affect these cycles is by building structures such as burrows, trails, latrines, and nests, each of which disturbs the soil and alters its biogeochemistry. In addition, because the effects of each species’ structures may be different, changes in the population distribution of animal species as the climate warms may lead to changes in Arctic soil cycles. This project is combining these two factors – herbivore structures and community change – and examining how changes in either may affect carbon and nutrient cycling in Arctic ecosystems. This research is expanding our understanding of Arctic systems and can be used to improve predictions of how the Arctic may respond to environmental change. This project includes mentorships of K-12 and college-aged students, public outreach in arctic communities, and dissemination of science to the public.Arctic herbivores, including small mammals, impact environmental processes that feedback on ecosystem function. While most research has focused on effects through herbivory, small mammals may also act as ecosystem engineers, modifying the biophysical environment around them. This project is examining how, and through what mechanisms, small mammal structures influence nutrient availability and microbial activity. The researchers are also evaluating how differences in the functional roles and abundances of two competitor small mammal species (brown and collared lemmings) may alter soil biogeochemical cycling. Near Utqiaġvik, Alaska, researchers are sampling soils from beneath four types of small mammal structures (runways, winter nests, latrines, and burrows) from each species to examine their impacts on soil biogeochemical responses. Using the proportional cover of each activity type on the landscape and their relative impacts on biogeochemical cycling, the data are then used to model the impacts of each species during the peak of their population cycle. This research is incorporating herbivores into the greater understanding of Arctic ecosystem function and is being used to improve a pre-existing ecosystem model to better predict carbon cycling in the Arctic.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.

北极苔原占地约6％的土地表面，但占世界土壤碳的25％。随着气候变暖，这种存储的碳被释放到大气中，从而进一步增强了气候变暖。正确对此反馈进行建模需要有关控制北极土壤中碳循环的信息。迄今为止，大多数对北极碳循环的研究都忽略了北极动物在控制土壤生物地球化学周期中所起的作用。动物可能影响这些周期的一种重要方法是建立诸如洞穴，小径，厕所和巢等结构，每种结构都会干扰土壤并改变其生物地球化学。此外，由于每个物种结构的影响可能不同，因此动物物种的种群分布变化，因为气候变暖可能会导致北极土壤周期的变化。该项目将这两个因素结合在一起 - 草食动物结构和社区变化 - 并研究了两者的变化如何影响北极生态系统中的碳和养分循环。这项研究正在扩大我们对北极系统的理解，可以用来改善对北极对环境变化的反应的预测。该项目包括K-12和大学生学生的精神训练，北极社区的公共宣传以及向公众传播科学。阿尔克草食动物，包括小型哺乳动物，影响反馈生态系统功能的环境过程。尽管大多数研究都专注于通过草食生物的作用，但小型哺乳动物也可以作为生态系统工程师，从而改变周围的生物物理环境。该项目正在研究小型哺乳动物结构如何以及如何通过哪些机制影响营养的可用性和微生物活性。研究人员还在评估两个竞争者小型哺乳动物物种（棕色和领）的功能作用和抽象差异。诱饵）可能会改变土壤生物地球化学循环。在阿拉斯加的Utqiaġvik附近，研究人员正在从每个物种的四种小型哺乳动物结构（跑道，冬季巢，厕所和毛刺）中取样土壤，以检查其对土壤生物地球化学反应的影响。利用每种活动类型对景观的比例覆盖及其对生物地球化学循环的相对影响，然后将数据用于模拟每个物种在人口周期的峰值中的影响。这项研究被纳入对北极生态系统功能的更深入的了解，并用于改善现有的生态系统模型，以更好地预测北极中的碳循环。该奖项反映了NSF的法定任务，并通过使用该基金会的知识分子和更广泛的影响来评估NSF的法定任务，并被视为珍贵的支持。

项目成果

Small but mighty: Impacts of rodent‐herbivore structures on carbon and nutrient cycling in arctic tundra

小而强大：啮齿动物和草食动物结构对北极苔原碳和养分循环的影响

• DOI: 10.1111/1365-2435.14127
• 发表时间: 2022
• 期刊: Functional Ecology
• 影响因子: 5.2
• 作者: Roy, Austin;Gough, Laura;Boelman, Natalie T.;Rowe, Rebecca J.;Griffin, Kevin L.;McLaren, Jennie R.
• 通讯作者: McLaren, Jennie R.