Tree rings as indicators of hydrological changes and past climate

树木年轮分析在提供环境代理（例如，温度、干旱、昆虫爆发）。在加拿大，树木每年都会产生年轮，它们分布广泛，通常可以存活几个世纪。因此，我们可以使用树木年轮特征来重建仪器记录之前的条件。我的研究的一个长期目标是发现新的树木年轮特征，并评估它们作为代理的用途。近年来，树木年轮的解剖异常已被广泛用作极端气候事件的指标。例如，霜环和光环提供了有关温度异常的信息，它们可以帮助根据过去和当前的气候来衡量未来的气候预测。有趣的是，光环是负相关的最大晚材密度，一个广泛使用的夏季温度代理。最大晚材密度也可以通过测量树木年轮的蓝色反射率来近似计算;这种技术在北美很大程度上没有得到充分利用。温尼伯大学树木生态学实验室正在产生重大影响的另一个领域是树木水文学。我们在使用洪水环和早材船的年复一年的测量来研究北方系统的长期水文变化方面处于领先地位。我们的最新工作与弥漫多孔物种允许确定一种新的水文代理的形式定期切向带的船只。 拟议的研究将沿着沿着两个主轴发展。第一个是树木水文学。我们将在时间上、地理上、跨物种和水文制度扩大我们的工作。其次，我们将探讨利用我们的大型木材收集在加拿大树木气候学的蓝色反射率的效用。将对包括温尼伯湖在内的马尼托巴的水文系统进行两项研究。另一个将决定如何环孔物种美国榆树应对洪水。第四个将评估重建渥太华河上游历史洪水的可能性。第五项研究将侧重于扩散多孔物种对洪水的响应。第六个项目的目标是重建全新世洪水动力学，重点是杜帕奎特湖的支流，魁北克。至少有四个项目也将涉及蓝色反射率，并涉及学生完成荣誉论文。总之，这项研究将使人们能够更好地了解树木的生长，并更好地可视化人类活动和/或自然变化带来的未来环境变化可能会影响加拿大人和他们的环境。这对加拿大水电部门和水资源管理者将是有益的。这个研究项目将为本科生和硕士生提供许多项目。由于它是实验室密集型的，它还将提供许多培训和就业机会。鉴于温尼伯大学对校园本土化的坚定承诺，我的一部分研究时间也将为土著学生提供培训机会。

Tree-ring analysis has a long history of providing environmental proxies (e.g., temperature, drought, insect outbreak). In Canada, trees produce annual tree rings, they are widely distributed and often live for centuries. We can thus use tree-ring traits to reconstruct conditions prior to instrumental records. A long-term objective of my research is to uncover new tree-ring traits and to evaluate their use as proxies. In recent years, anatomical abnormalities in tree rings have become widely used as indicators of extreme climate events. For example, frost and light rings provide information about temperature anomalies and they can help gauge future climate projections in light of past and current climates. Interestingly, light rings are inversely related to maximum latewood density, a widely used summer temperature proxy. Maximum latewood density can also be approximated by measuring the blue reflectance of trees rings; a technique largely underutilized in North America. Another area in which the University of Winnipeg DendroEcology Laboratory is having significant impacts is dendrohydrology. We are leaders in the use of flood rings and year-to-year measurements of earlywood vessels to study long-term hydrological variability in boreal systems. Our latest work with diffuse-porous species has allowed to identify a novel hydrological proxy in the form of periodic tangential band of vessels. The proposed research will develop along two main axes. The first is dendrohydrology. We will expand our work temporally, geographically, across species and hydrological regimes. Second, we will explore the utility of blue reflectance in Canadian dendroclimatology taking advantage of our large wood collection. Two studies will be led on hydrological systems in Manitoba including Lake Winnipeg. Another will determine how ring-porous species American elm respond to flooding. A 4th one will evaluate the possibility to reconstruct historical flooding for the upper Ottawa River. A 5th study will focus on the response of diffuse-porous species to flooding. A 6th one will aim at reconstructing the Holocene flood dynamics focusing on Lake Duparquet's tributaries, Quebec. At least, four projects will also deal with blue reflectance and involve students completing an honours thesis. In conclusion, this research will allow to better understand tree growth and to better visualize how future environmental changes brought by human activities and/or natural variations may impact Canadians and their environment. It will be helpful to the Canadian Hydropower sector and water resource managers. This research program will provide many projects for both undergraduate and MSc students. Given it is laboratory intensive, it will also provide many training and employment opportunities. Given the strong commitment of the University of Winnipeg towards campus indigenization, a portion of my research time will also be going to provide training opportunities to Indigenous students.