Developing new approaches to track environmental change using lake sediment archives.

我的研究和HQP培训旨在回答需要从长远角度看待人为干扰和环境扰动对生态系统的影响的问题。这种长期观点是必要的，因为大多数环境研究都受到短期尺度的限制，无法充分估计自然的可变性。我的大部分研究和HQP培训都集中在湖泊沉积岩心上，作为重建长期环境变化的档案。在这里，我建议通过开发重建湖泊沉积物环境变化的新方法来继续推进这一领域。具体地说，我建议开发和应用新的工具来展示变暖的北方气候和迁徙动物如何改变水环境，并研究如何在整个全新世湖泊沉积物岩心中重建这些过程。最近，我的实验室的分析进展开发了有针对性的分析方法，用于分析来源特定的标志，以研究湖泊异地物质的变化，例如，表明麦肯齐野牛保护区的湖泊扩张是近几个世纪来前所未有的。我最近扩大了这项工作，开发了“非定向生物标记物发现”，以在不同生态区(如北冰洋和苔原湖泊)的沉积物中识别新的持久性有机标记物，努力展示加拿大的生态系统在最近几个世纪和几千年里发生了怎样的变化。这一新方法提供了传统上用于其他学科的分子标记发现方面独特的HQP培训机会，并将其独特地应用于沉积物研究。具体地说，我建议识别并应用下一代沉积物标记物来确定，例如，在前几个世纪，根据放射性年龄测定的湖泊沉积物岩心中的气候变化，树线是如何变化的。我建议研究的另一种方法是开发保存在湖泊沉积物岩心中的标记物，以重建来自迁徙动物和早期人类住区的输入，以研究这些种群的自然变异性。最近，我的实验室改进了粪便甾醇和甾醇的使用，以重建来自海鸟的湖泊沉积物中的营养物质，提高了对粪便输入湖泊的甾醇指纹来源进行识别的可能性。使用多代理方法，我建议收集邻近海鸟群落和人类住区的沉积物岩芯，努力通过追踪湖泊沉积物岩芯的特定来源标记来确定种群的到达和长期稳定性，并利用这些信息来解决与保护生物学、生态系统动力学以及生态系统变化的自然和人为驱动因素有关的关键问题。

My research and HQP training aims to answer questions requiring a long-term perspective on the effects of anthropogenic disturbances and environmental perturbations on ecosystems. This long-term perspective is needed because most environmental studies are limited by short time scales that do not permit sufficient estimations of natural variability. I focus much of my research and HQP training on lake sediment cores as archives for reconstructing long term environmental change. Here I propose to continue to advance this field by developing new approaches for reconstructing environmental change in lake sediments. Specifically, I propose to develop and apply new tools to demonstrate how aquatic environments have been altered by warming northern climates and migratory animals, and examine how these processes may be reconstructed throughout the Holocene in lake sediment cores.Recent analytical advances in my laboratory have developed targeted analytical methods for analyzing source-specific markers to study changes in allochthonous matter to lakes to show, for example, that lake expansion in the Mackenzie Bison Sanctuary is unprecedented in recent centuries. I have recently augmented this work by developing “non-targeted biomarker discovery” to identify new persistent organic markers in sediments from different ecozones (such as Boreal and Tundra lakes) in an effort to show how Canada's ecosystems have changed in recent centuries and millennia. This new approach provides unique HQP training opportunities in molecular marker discovery that is traditionally used in other disciplines, and uniquely applying them to sediment studies. Specifically, I propose to identify and apply the next generation of sediment markers to determine, for example, how tree line has shifted in previous centuries in response to changing climate in radiometrically dated lake sediment cores.Another methodology I propose to examine is to develop markers preserved in lake sediment cores to reconstruct inputs from migratory animals and early human settlements to study the natural variability of these populations. Recently, my lab has advanced the use of fecal sterols and stanols to reconstruct nutrients to lake sediments from seabirds, raising the potential for sterol fingerprinting sources of fecal inputs to lakes. Using a multi-proxy approach, I propose to collect sediment cores adjacent to seabird colonies and human settlements in an effort to determine the arrival and long-term stability of populations by tracking source-specific markers to lake sediment cores, and to use this information to address key issues linked to conservation biology, ecosystem dynamics, and natural versus anthropogenic drivers of ecosystem change.