Paleoecological studies across northwestern Canada (logistical support)

加拿大西北部的古生态研究（后勤支持）

• 批准号: 361670-2008
• 负责人: Pisaric, Michael
• 金额: $ 1.09万
• 依托单位: Brock University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Northern Research Supplement
• 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=572785
• 关键词: Paleoecological; studies; across; northwestern; Canada

Northwestern Canada has experienced the greatest warming in Canada during the past 50 years and numerous dendroclimatological studies also suggest that the 20th century may have been the warmest period during the past 3 centuries or more. Climate modeling experiments suggest temperatures will continue to increase in this region during the current century. Such increases in temperature are likely to have dramatic impacts on northern ecosystems, including altering the composition and position of some biomes, altering the response of biotic communities to climate or possibly changing the frequency and intensity of disturbance events. This research will have three main objectives: 1. Determining the controls on tree growth at northern treeline. To investigate this automatic point dendrometers will be used to measure tree growth at very high temporal resolution (every 15 mins.) during the growing season in the eastern Mackenzie Delta region. Onsite climate data will also be collected using a portable weather station. The climate data will be used to develop a mechanistic model of tree growth which will greatly improve our understanding of climate-growth relations. 2. Investigating the utility of alternative proxy indicators from tree ring growth records for studies of past climate. Given divergence between tree growth and climate, alternative data sources need to be investigated to develop accurate reconstructions of past climate and to put recent climate change in a long term context. We will expand on our initial work developing annually resolved records of stable carbon and oxygen isotopes from tree rings. We hope to develop a millennial length isotope record from northwestern Canada so that comparisons can be made between recent warming and the so-called Medieval Warm Period. 3. Determining the natural frequency of forest fires and the impact of fire on succession and development in boreal type forests of northwestern Canada. Using high-resolution lake sediment records and tree establishment and fire scar records we will reconstruct fire frequency during the Holocene. These types of records will help us better constrain the natural fire frequency in the northwest of Canada.

在过去的50年里，加拿大西北部经历了加拿大最大的变暖，许多树木气候学研究也表明，世纪可能是过去3个世纪或更长时间里最温暖的时期。气候模拟实验表明， 在本世纪，这种温度上升可能对北方生态系统产生巨大影响，包括改变某些生物群落的组成和位置，改变生物群落对气候的反应，或可能改变扰动事件的频率和强度。这 研究的主要目的有三：北方树线林木生长控制措施的确定。为了研究这种自动点式树木生长计将用于测量树木生长在非常高的时间分辨率（每15分钟）。在生长季节在东部麦肯齐三角洲地区。还将使用便携式气象站收集现场气候数据。气候数据将用于制定 树木生长的机械模型，这将大大提高我们对气候与生长关系的理解。2.从树木年轮生长记录调查替代性代用指标对过去气候研究的效用。鉴于树木生长和气候之间的差异，需要调查替代数据来源， 准确重建过去的气候，并将最近的气候变化放在长期背景下。我们将扩大我们的初步工作，开发每年解决记录稳定的碳和氧同位素从树木年轮。我们希望从加拿大西北部开发一个千年长度的同位素记录，以便在最近的变暖和所谓的中世纪温暖期之间进行比较。3.确定 森林火灾的自然频率和火灾对加拿大西北部北方森林演替和发展的影响。利用高分辨率湖泊沉积物记录、树木建立和火痕记录，我们将重建全新世期间的火灾频率。这些类型的记录将帮助我们更好地限制加拿大西北部的自然火灾频率。