Impacts of climatic change and environmental stress on aquatic ecosystems

气候变化和环境压力对水生生态系统的影响

• 批准号: 170043-2008
• 负责人: Pienitz, Reinhard
• 金额: $ 3.06万
• 依托单位: Université Laval
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=569536
• 关键词: Impacts; climatic; change; environmental; stress

To explore the potential responses of northern freshwater ecosystems and their watersheds to climate change and to place instrumental temperature records into a long-term perspective, we will use a multi-proxy paleolimnological approach to generate detailed paleoclimatic and paleoenvironmental records from lake sediment archives in the eastern Canadian Arctic. These records will be synthesized and the resulting time series analyzed to allow regional comparisons with ice core data from Greenland as well as with paleoceanographic data from surrounding marine environments. Our central objective is to generate a network of decadal-millennial scale records of quantitative variations in limnological parameters that will provide a better understanding of the range of natural environmental variability in northeastern Canada, and allow us to explore fundamental questions concerning postglacial ecosystem succession in northern landscapes. In our research to date we have developed new analytical techniques and transfer functions for proxy indicator organisms (diatoms and chironomids) that have generated new insights into Holocene climatic and environmental variability in northern Québec (Nunavik), Labrador and Southampton Island (Nunavut). Over the term of the next Discovery grant, we will extend our biostratigraphical time-series approach into the Foxe Basin region of Nunavut (65°-70°N; 71°-85°W), which occupies a key position between the High Arctic where lakes and the cryosphere show signs of pronounced warming in recent decades, and the Subarctic (Nunavik and Labrador) where these changes are not yet detectable. Building on strong links between paleolimnology and contemporary limnology, our interpretations of past changes in northern lakes and ponds will be combined with research into the present-day functioning of these ecosystems. We will focus especially on developing a better understanding of limnological conditions during early lake evolution in newly formed landscapes and their repercussions on aquatic biota. We will therefore examine the conditions in lakes in front of retreating glaciers on Bylot Island (73°N) that have affinities with early developmental phases in the history of northern lakes.

为了探索北方淡水生态系统及其流域对气候变化的潜在响应，并将仪器温度记录放在长期的角度来看，我们将使用多代理古湖沼学的方法来产生详细的古气候和古环境记录在加拿大北极东部的湖泊沉积物档案。将对这些记录进行综合，并对由此产生的时间序列进行分析，以便与格陵兰的冰芯数据以及周围海洋环境的古海洋学数据进行区域比较。我们的中心目标是产生一个网络的十年-千年尺度记录的湖沼参数的定量变化，这将提供一个更好的了解在加拿大东北部的自然环境变化的范围，并使我们能够探索有关冰后期生态系统演替在北方景观的基本问题。 在我们的研究中，到目前为止，我们已经开发出新的分析技术和传递函数的代理指示生物（硅藻和摇蚊），产生了新的见解全新世气候和环境变化在北方魁北克（努纳维克），拉布拉多和南安普顿岛（努纳武特）。在下一次发现资助期间，我们将把我们的生物地层学时间序列方法扩展到努纳武特（北纬65°-70 °;西经71°-85 °）的福克斯盆地地区，该地区位于高北极和亚北极（努纳武特和拉布拉多）之间的关键位置，在高北极，湖泊和冰冻圈显示出近几十年来明显变暖的迹象，而在亚北极，这些变化尚未检测到。建立在古湖沼学和当代湖沼学之间的紧密联系，我们对北方湖泊和池塘过去变化的解释将与对这些生态系统当今功能的研究相结合。我们将特别关注在新形成的景观和水生生物群的影响，在早期湖泊演变的湖沼条件更好地了解。因此，我们将研究拜洛特岛（73°N）冰川退缩前的湖泊状况，这些湖泊与北方湖泊历史上的早期发展阶段有密切关系。