DISSERTATION RESEARCH: Effects of Climate-Induced Changes in Generalist Predators on the Structure and Function of Arctic Food Webs

随着气候变化的预测，有必要了解生物体对气候驱动因素的适应如何适应更广泛的生态背景。北极生态系统的变化具有特别重要的意义，因为这一区域正在经历地球上最快的气候变化速度。此外，北极冻土带的土壤储存了大量的有机物，这些有机物可以通过微生物群落的分解以二氧化碳和甲烷的形式释放出来。北极地区更快的分解速度可能会对全球气候变化产生积极的反馈。负责分解的微生物群落的组成和活动受到土壤中无脊椎动物的影响，而无脊椎动物本身受到蜘蛛等捕食者的调节。在其他生态系统中，蜘蛛捕食的级联效应被发现间接地抑制了分解。如果北极也发生这种情况，蜘蛛可以通过减缓冻土带土壤中碳的释放来提供重要的生态系统服务。这个项目利用对蜘蛛密度和温度的实验操作，来研究蜘蛛和它们的猎物之间的关系如何影响北极冻土带的微生物分解速度。研究结果将为全球气候变化与当地社区结构和功能变化之间的潜在反馈提供新的见解。Co-Pi(Amanda Koltz)致力于为不同背景的学生提供更多的科学机会。为了这个项目，她与四名本科生一起工作并培训了他们，其中三名是女性，其中一名是非裔美国人和印第安人后裔。在阿拉斯加，科尔茨与阿拉斯加乡村荣誉学院的农村和阿拉斯加原住民高中生一起工作。她还将在阿拉斯加主持2012年实地考察季的一名K-12教师(PolarTREC计划)，以便为教师提供参与实践实地研究的机会，并帮助将北极科学带回课堂。

With forecasted changes in climate, it is necessary to understand how organismal adaptations to climatic drivers fit into a broader ecological context. Changes in artic ecosystems are of particular significance because this region is experiencing the fastest rate of climate change on the planet. Moreover, the soils of the arctic tundra store large amounts of organic matter that could be released as carbon dioxide and methane through decomposition by the microbial community. Faster rates of decomposition in the Arctic could result in positive feedbacks on global climate change. The composition and activity of the microbial communities that are responsible for decomposition are affected by invertebrates in the soil, which are themselves are regulated by predators such as spiders. In other ecosystems, cascading effects of spider predation have been found to indirectly inhibit decomposition. If this also occurs in the Arctic, spiders could provide an important ecosystem service by slowing the release of carbon from tundra soils. This project uses an experimental manipulation of spider density and temperature to examine how the relationship between spiders and their prey affects rates of microbial decomposition in the arctic tundra. Results will provide new insights into the potential feedbacks between global climate change and local changes in community structure and function. The Co-PI (Amanda Koltz) is dedicated to furthering opportunities in science for students from diverse backgrounds. For this project, she has worked with and trained four undergraduate students, three of which are women, and one of whom is of African American and Native American descent. In Alaska, Koltz has worked with rural and Alaska Native high school students from The Rural Alaska Honors Institute. She will also host a K-12 teacher (PolarTREC Program) in Alaska for the 2012 field season in order to provide the teacher with an opportunity to participate in hands-on field research and help bring arctic science back to the classroom.