Paleolimnology and Environmental Change

古湖泊学和环境变化

• 批准号: RGPIN-2016-04347
• 负责人: Cumming, Brian
• 金额: $ 2.91万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=687931
• 关键词: Paleolimnology; Environmental; Change

Warmer temperatures over the last century and projections of unprecedented increases in temperature over the next 20-50 years, has led to concern on the potential impacts of climate change on aquatic ecosystems. Research in my lab focuses on understanding how lakes have responded to climate and other natural or human-induced factors in the past, by the analysis of the physical, chemical and biological information preserved in lake sediment cores. Paleolimnological studies can provide important insights on the sensitivity of aquatic and terrestrial ecosystems to climate change. This proposal seeks to provide research and training opportunities to investigate how warmer periods in the past influenced the water balance and aquatic production of boreal lakes from northern Ontario, with a focus on the Holocene Thermal Maximum (HTM), a warmer period circa 8,000 to 4,000 years ago. During the HTM, northwest Ontario was characterized by a parkland-type forest with scrubs and grasses, low lake-levels, and frequent fires. However, information on how lakes responded to the HTM, across the humid regions of northern Ontario from Sioux Lookout to Timmins (a distance of over 700 km) are largely unknown. It is likely that the HTM influenced this entire region, since the easternmost region of northern Ontario, near Timmins, saw white pine replacing spruce c. 7,000 years ago, before returning to a spruce forest circa 4,000 years ago. We propose to develop and apply approaches, using physical, chemical and biological proxies, from both near-shore and deep-water cores, to provide information on how lake levels and production changed across the central and eastern boreal regions of Ontario, as well as provide information on changes in vegetation and fire over the Holocene. Given that the estimated temperature changes during the HTM were small relative to the projected warming, information from this study will provide an assessment of vulnerability to possible droughts, algal blooms, and fires associated with living in a warmer world.**** This proposal also seeks support to provide training and research opportunities to understand the possible role of recent climate change on lakes from the Adirondack region (New York, USA). Most aquatic systems in the northeast are now influenced by multiple local and regional stressors. We have developed a network of 31 reference lakes, that were chosen from over 1400 lakes, to have little impact from local human activities (roads, logging, settlement, fish stocking) and the direct impacts of acid deposition. This network of lakes will be studied to assess how biological assemblages of algae and invertebrates have changed in the absence of the most common environmental stressors to aquatic systems in the northeast (i.e. acid deposition, watershed disturbances, fish stocking), thereby allowing an assessment of recent changes related to climate and other broad-scale regional stressors.**** **

上个世纪的气温升高以及对未来20-50年气温空前升高的预测，已引起人们对气候变化对水生生态系统潜在影响的关注。我实验室的研究重点是通过分析湖泊沉积物岩心中保存的物理、化学和生物信息，了解湖泊过去是如何对气候和其他自然或人为因素做出反应的。古湖泊学研究可以为水生和陆地生态系统对气候变化的敏感性提供重要的见解。该提案旨在提供研究和培训机会，以调查过去温暖时期如何影响安大略省北部北方湖泊的水平衡和水生生产，重点关注全新世热极大期（HTM），这是一个大约8000至4000年前的温暖时期。在HTM期间，安大略省西北部以灌木和草地为主的公园型森林为特征，湖泊水位低，火灾频发。然而，从苏望湖到蒂明斯（超过700公里的距离）横跨安大略省北部潮湿地区的湖泊如何应对HTM的信息在很大程度上是未知的。热媒很可能影响了整个地区，因为安大略省北部最东部的地区，Timmins附近，大约7000年前，白松取代了云杉，然后在大约4000年前又回到了云杉森林。我们建议开发和应用方法，使用来自近岸和深水岩心的物理、化学和生物代用物，提供安大略省中部和东部北方地区湖泊水位和产量变化的信息，以及提供全新世植被和火灾变化的信息。鉴于HTM期间估计的温度变化相对于预估的变暖较小，本研究的信息将提供与生活在更温暖的世界中有关的可能的干旱、藻华和火灾的脆弱性评估。****本提案还寻求支持，以提供培训和研究机会，以了解最近气候变化对阿迪朗达克地区（美国纽约）湖泊的可能作用。东北地区大多数水生系统现在受到多种局部和区域压力源的影响。我们从1400多个湖泊中选择了31个参考湖泊，建立了一个网络，这些湖泊几乎不受当地人类活动（道路、伐木、定居、鱼类放养）的影响，也不受酸沉积的直接影响。将研究这一湖泊网络，以评估藻类和无脊椎动物的生物组合在东北水生系统缺乏最常见的环境压力因素（即酸沉积、流域干扰、鱼类放养）的情况下是如何变化的，从而能够评估与气候和其他大范围区域压力因素有关的近期变化。**** **