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.

北极苔原覆盖了地球约 6% 的陆地表面，但储存了世界 25% 的土壤碳。随着气候变暖，这些储存的碳会释放到大气中，进一步加强气候变暖的模拟需要有关控制因素的信息。迄今为止，大多数关于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循环中可能发挥的作用，动物影响这些循环的一种重要方式是建造洞穴、小径等结构。厕所和巢穴，它们都会扰乱土壤并改变其生物地球化学。此外，由于每个物种的结构的影响可能不同，随着气候变暖，动物物种种群分布的变化可能会导致北极土壤的变化。该项目将食草动物结构和群落变化这两个因素结合起来，并研究两者的变化如何影响北极生态系统的碳和养分循环。这项研究正在扩大我们对北极系统的了解，并可用于改进预测。该项目导师包括 K-12 和大学生的船只、北极社区的公共宣传以及向公众传播科学。北极食草动物，包括小型哺乳动物，影响环境过程，虽然大多数研究都集中在食草性的影响上，但小型哺乳动物也可以充当生态系统工程师，改变它们周围的生物物理环境，该项目正在研究小型哺乳动物的结构如何以及通过什么机制影响营养的可用性和影响。研究人员还在评估两种竞争性小型哺乳动物（棕色旅鼠和颈旅鼠）的功能作用和丰度差异如何改变阿拉斯加乌特恰维克附近的土壤生物地球化学循环。每个物种的结构（跑道、冬季巢穴、厕所和洞穴），利用每种活动类型对景观的覆盖比例及其对土壤生物地球化学反应的影响。这项研究将食草动物纳入对北极生态系统功能的更深入了解中，并用于改善现有的生态系统。该奖项反映了 NSF 的法定使命，并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，被认为值得支持。

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.