Gap dynamics in trembling aspen stands, dendroclimatology of jack pine and tree-ring anomalies in conifers from Manitoba

该研究计划是我以前NSERC研究计划的延续，它有三个主要组成部分。我的第一个兴趣是从事森林干扰和动态的研究。我打算把重点特别放在次生林干扰颤抖白杨为主的森林的北部平原的马尼托巴。需要阐明的问题之一是关于存在于白杨林隙形成和森林帐篷毛虫（FTC）爆发的频率/严重程度之间的关系。在北方平原的马尼托巴，榛子也构成了一个主要的竞争对手，森林再生，我们要量化的林下物种的响应，在环境条件的变化所造成的开放的树冠。第二个组成部分涉及北方树种短叶松在马尼托巴整个范围内的气候敏感性。该项目将与我们最近在马尼托巴鸭山地区的光环工作保持连续性，除其他外，还将涉及使用树木年轮密度测定法来重建过去的凉爽生长季节。第三部分将涉及研究树木年轮异常（木材解剖学），也研究落叶对短叶松木质部形成的影响。我们最近开始研究来自马尼托巴西部的短叶松的光环，我们还开始了一些关于来自马尼托巴东部的短叶松密度波动的工作。在我们的采样中，我们还观察到一个新的树木年轮异常的形式白色早材环在许多针叶树种。我们将专门研究短叶松芽虫对树木年轮解剖的影响，并研究马尼托巴目前该物种分布范围外的短叶松种植园。这些研究项目将产生与加拿大中部森林管理有关的具体成果，并更好地了解气候如何影响加拿大中部的树木生长。这些项目是马尼托巴省独有的，我们对许多树木年轮异常的分析是必不可少的：1）了解环境波动如何影响树木生长，2）使用树木年轮分析更好地重建过去的气候波动。

The proposed research program is a continuity of my previous NSERC research proposals and it has three major components. My first interest is to pursue research on forest disturbances and dynamics. I intend to focus particularly on secondary forest disturbances in trembling aspen dominated forests of the boreal plains of Manitoba. One of the questions that needs to be elucidated concerns the relationship that exist between gap formation in aspen stands and the frequency/severity of forest tent caterpillar (FTC) outbreaks. In the boreal plains of Manitoba, hazelnut also constitutes a major competitor to forest regeneration and we want to quantify the response of understory species to change in environmental condition resulting from the opening of the canopy. The second component concerns the climate sensitivity of the boreal tree species jack pine across its range in Manitoba. This project will be in continuity with our recent work on light rings in the Duck Mountain region of Manitoba and will also involved, among others, the use of tree-ring densitometry to reconstruct past cool growing season. The third component will involve studying tree-ring anomalies (wood anatomy) and also the study of the influence of defoliation on xylem formation in jack pine trees. We recently started to look at light rings in jack pine from western Manitoba and we also initiated some work on density fluctuation in jack pine trees from eastern Manitoba. Across our sampling we also observed a new tree-ring anomaly in the form of white earlywood ring in numerous conifer species. We will specifically look at the impact of jack pine budworm on tree ring anatomy and also look at jack pine plantation outside the current range of distribution of the species in Manitoba. These research projects will have specific outcomes related to forest management in central Canada as well as better understand of how climate is affecting tree growth in central Canada. These projects are unique to Manitoba and our analysis of numerous tree-ring anomalies is essential 1) to understand how environmental fluctuations are affecting tree growth and 2) to provide better reconstruction of past climate fluctuations using tree-ring analysis.