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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=648404
• 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.**** **

上个世纪气温变暖，以及预计未来20-50年气温将出现前所未有的上升，导致人们对气候变化对水生生态系统的潜在影响感到担忧。我实验室的研究重点是通过分析保存在湖泊沉积物岩芯中的物理、化学和生物信息，了解湖泊过去对气候和其他自然或人为因素的反应。古湖沼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。这项提议旨在提供研究和培训机会，以调查过去较温暖的时期如何影响安大略省北部北方湖泊的水平衡和水生生物产量，重点是全新世最高温度(HTM)，这是大约8,000到4,000年前的较温暖时期。在HTM期间，安大略省西北部的特点是公园类型的森林，有灌木丛和草，湖面低，火灾频繁。然而，关于湖泊如何对HTM做出反应的信息，从苏瞭望到蒂明斯(距离超过700公里)，横跨安大略省北部潮湿地区的信息基本上是未知的。很可能是HTM影响了整个地区，因为在安大略省北部最东端的蒂明斯附近，7000年前白松取代了云杉，大约4000年前又回到了云杉林。我们建议开发和应用从近岸和深水岩心使用物理、化学和生物指标的方法，以提供关于安大略省中部和东部北部地区湖泊水位和产量变化的信息，并提供关于全新世植被和火灾变化的信息。考虑到HTM期间估计的温度变化与预计变暖相比很小，这项研究的信息将提供对与生活在更温暖的世界中相关的可能的干旱、藻类水华和火灾的脆弱性的评估。*该建议还寻求支持，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。东北部的大多数水生系统现在都受到多个局部和区域压力的影响。我们从1400多个湖泊中挑选了31个参照湖，建立了一个参照湖网络，以减少当地人类活动(道路、伐木、定居点、鱼类放养)和酸沉积的直接影响。将对这一湖泊网络进行研究，以评估在不存在对东北部水生系统最常见的环境压力(即酸沉积、流域干扰、鱼类放养)的情况下，藻类和无脊椎动物的生物组合是如何变化的，从而能够评估与气候和其他大范围区域压力有关的最新变化。