Limnology and paleoecology of lakes

北极地区已被多次确定为全球环境变化研究的领头羊。然而，由于缺乏长期数据，无法确定许多生态系统变化的时间和幅度，也无法检验假设、定义自然变异性和评估模型。因此，间接的替代方法，如使用保存在湖泊沉积物（即古湖沼学）的信息，必须用来解决许多科学和社会相关的问题。在我在北极的26年研究计划中，与我们正在进行的古湖沼学工作相吻合，我们记录了显著的湖沼学变化，因为北极的高池塘随着变暖而变得不那么冰覆盖和变浅，直到许多较小的地点最终在2006年7月完全干涸。 我们将研究这些前所未有的生态变化如何影响北极生态系统，以及其他北极地区的古湖泊和生态变化。 第二个新的研究领域将集中我们的方法亚北极泥炭地配置文件，这可能提供更高的时间分辨率的环境变化比北极湖泊沉积物，并可能更密切地联系到降水和蒸发率。我们的主要重点将是从哈德逊湾低地地区，这是一个地区，是我们的气候和环境变化的理解至关重要的泥炭和永久冻土核心的横断面。 与基于过程的科学家合作，对15个湖泊进行平行的古湖泊学研究，将补充这一北半球至亚北极的样带，并确定与气候有关的冰盖变化和/或热分层模式如何影响这些研究不足的地区的湖泊，毗邻温带和亚北极生态系统。最后，我们将开发和应用新的古湖沼学方法（主要基于无脊椎动物指标）来跟踪一个新的和以前未被认识到的环境问题，影响世界各地的软水北方湖泊：湖水钙浓度的下降。

Arctic regions have been repeatedly identified as bellwethers for the study of global environmental change. However, due to the lack of long-term data, it is impossible to determine the timing and magnitude of many ecosystem changes, and to test hypotheses, define natural variability, and evaluate models. Consequently, indirect proxy methods, such as using information preserved in lake sediments (i.e. paleolimnology) must be used to address many scientifically and socially-relevant questions. During my 26 year research program in the Arctic, which dovetails with our ongoing paleolimnological work, we have recorded marked limnological changes as high Arctic ponds become less ice-covered and shallower with warming until many of the smaller sites finally dried up totally in July 2006. We will study how these unprecedented ecological changes are affecting Arctic ecosystems, as well as comparable paleolimnological and ecological changes in other Arctic regions. A second new research area will focus our approaches on subarctic peatland profiles, which potentially offer higher temporal resolution of environmental change than Arctic lake sediments, and may be more closely linked to precipitation and evaporation ratios. Our main focus will be a transect of peat and permafrost cores from the Hudson Bay Lowlands region, which is a region that is critically important for our understanding of climatic and environmental change. A parallel paleolimnological study of 15 lakes, working in collaboration with process-based scientists, will complement this boreal to subarctic transect, and determine how climate-related changes in ice cover and/or thermal stratification patterns are affecting lakes in these poorly studied regions, bordering on temperate and sub-arctic ecosystems. Finally, we will develop and apply new paleolimnological methods (based largely on invertebrate indicators) to track a new and previously under-recognized environmental problem affecting softwater boreal lakes around the world: the decline in lakewater calcium concentrations.