Trees as indicators of past climates and forest dynamics in Central Canada

树木作为加拿大中部过去气候和森林动态的指标

• 批准号: RGPIN-2016-05151
• 负责人: Tardif, Jacques
• 金额: $ 2.04万
• 依托单位: University of Winnipeg
• 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=682929
• 关键词: Trees; indicators; past; climates; forest

The research focuses on how environmental factors (e.g., climate, insect, disease, fire) affect tree growth and tree-ring formation. In Canada, trees produce annual tree rings and often live for many centuries. We can thus utilize them or their tree-ring characteristics to reconstruct conditions prior to recording by instruments. This capability allows us for example to gain information on climate variability prior to European settlement. To do so however, we need a clear understanding of how today's environmental conditions affect tree growth in various species and habitats. This research goes from studying wood anatomy to the quantification of the impact of large scale phenomena like insect outbreaks, forest fires, and climate extremes. Tree-ring research not only allows for a better understanding of growth but it also allows to foresee how future environmental changes brought by human activities and/or natural variations may impact Canadians and their environment. This research mainly focuses on central Canada. First, we will study tree-ring anomalies (e.g., false rings, frost rings) and the factors (e.g., insect, disease, drought, temperature) that trigger their formation. One of the questions arising from our research is why are trees in a given area not all recording a specific event? For example, what makes a tree a good recorder of drought and not another? Second, we intend to study the impacts of Lake Winnipeg hydrological changes on growth and wood anatomy of shoreline deciduous trees species. Third, the jack pine network of tree-ring chronologies that we are developing for Manitoba will be completed and will continue to be used to reconstruct dynamical processes like insect outbreaks and climate variability. Fourth, we will pursue our millennia forest fire reconstruction. This project involves to quantify and analyze the charcoal particles that were deposited in lake sediments over the last few millennia and that were produced by forest fires. Fifth, we will expand our research to wetlands and in particular to back spruce growth in peatland a habitat that has been little considered by tree-ring scientists despite their abundance in Canada and worldwide. We are interested in the potential that trees offers for long-term understanding of hydroclimatic changes. In conclusion, this research will allow to better understand tree growth and to better visualize the past and current variability in climate and other environmental factors in Interior North America. Given that our research is laboratory intensive, it does benefit both undergraduate and graduate students by providing many training and employment opportunities. The ecological information generated will also be helpful to forest managers (e.g., Parks Canada, Forestry Branch) as our research contributes to better manage these ecosystems.

研究重点是环境因素（例如，气候、昆虫、疾病、火灾）影响树木生长和树轮形成。在加拿大，树木每年都会产生年轮，并且通常可以存活几个世纪。因此，我们可以利用它们或它们的年轮特征来重建仪器记录之前的条件。例如，这种能力使我们能够获得欧洲人定居之前的气候变化信息。然而，要做到这一点，我们需要清楚地了解当今的环境条件如何影响各种物种和栖息地的树木生长。这项研究从研究木材解剖到量化昆虫爆发，森林火灾和极端气候等大规模现象的影响。树木年轮研究不仅可以更好地了解生长情况，而且还可以预测人类活动和/或自然变化带来的未来环境变化可能对加拿大人及其环境产生的影响。这项研究主要集中在加拿大中部。首先，我们将研究树木年轮异常（例如，假环，霜环）和因素（例如，昆虫、疾病、干旱、温度）触发它们形成。我们研究中的一个问题是，为什么在一个特定区域的树木并不都记录了一个特定的事件？例如，是什么让一棵树成为干旱的好记录者而不是另一棵？其次，我们打算研究温尼伯湖水文变化对海岸线落叶树种的生长和木材解剖的影响。第三，我们正在为马尼托巴开发的短叶松树轮年表网络将完成，并将继续用于重建昆虫爆发和气候变化等动态过程。第四，我们将继续进行千年森林火灾重建。该项目涉及量化和分析过去几千年来沉积在湖泊沉积物中的木炭颗粒以及森林火灾产生的木炭颗粒。第五，我们将把研究范围扩大到湿地，特别是泥炭地的云杉生长，尽管泥炭地在加拿大和世界各地都很丰富，但树木年轮科学家很少考虑这种栖息地。我们感兴趣的潜力，树木提供长期了解水文气候变化。总之，这项研究将有助于更好地了解树木生长，并更好地可视化北美内陆气候和其他环境因素的过去和当前变化。鉴于我们的研究是实验室密集型的，它确实通过提供许多培训和就业机会使本科生和研究生受益。所产生的生态信息也将有助于森林管理人员（例如，加拿大公园，林业分支），因为我们的研究有助于更好地管理这些生态系统。