Understanding carbon and nitrogen transformation in sub-boreal and boreal conifer forests using foliar and dendro-chemical analyses.

北方和亚北方森林对不列颠哥伦比亚省北部和育空地区的经济非常重要，因为它们拥有木材和非木材资源和便利设施。气候变化、森林管理和森林干扰现在正以各种各样的方式改变着这些森林，我们现在才刚刚开始了解这些方式。这项提议旨在研究这些森林可能如何应对这些最近的变化的三个不同和独特的方面。这三个目标都建立在我实验室目前正在进行的现有项目的基础上。(1)我们可以研究森林的健康和生长与气候的关系的一种方法是通过观察每年在树木中放置的年轮的宽度。我建议开发一种新的木材化学方法，以帮助我们了解未来对育空地区白云杉生长的水分和营养限制的可能性。(2)在第二个项目中，我建议基于我的实验室的经验结果开发一个动态的氮和碳模型。这个模型将预测在不同的蓝藻丰度、林分和气候条件下，由栖息在树上/固定氮气的蓝藻所导致的亚北方云杉和冷杉树的生长。(3)在第三个也是最后一个项目中，我建议研究一组鲜为人知的森林植物的盛行率、重要性和功能，这些植物通过地下真菌连接部分(混合营养生物)或全部(真菌异养植物)生活在相邻的寄主树木上。这些植物不仅对亚北方森林的植物多样性很重要，而且可能成为森林健康的重要指标。最近一次由气候变化促成的干扰，山松甲虫疫情，创造了一个很好的自然实验室，在失去许多树木宿主后，研究这些迷人的植物之间的相互作用。

Boreal and sub-boreal forests are incredibly important to the economies of northern British Columbia and the Yukon Territory for both timber and non-timber resources and amenities. Climate change, forest management, and forest disturbance are now altering these forests in a myriad of ways that we are now only beginning to understand. This proposal aims to study three different and unique aspects of how these forests may be responding to these recent changes. All three objectives build on existing projects currently going on in my lab. (1) One way that we can study the health and growth of our forests as they relate to climate is by looking at the width of the annual rings that are laid down each year in the wood of trees. I am proposing to develop a new wood chemistry approach to help us understand the likelihood of future water and nutrient limitations to white spruce growth in the Yukon. (2) In a second project, I propose to develop a dynamic nitrogen and carbon model based on empirical results from my lab. This model would predict sub-boreal spruce and fir tree-growth resulting from tree-dwelling/N2-fixing cyanolichens under a variety of cyanolichen abundances, forest stand and climate conditions. (3) In the third and final project, I propose to study the prevalence, importance and function of a poorly understood group of forest plants that live in part (mixotrophs) or in whole (mycoheterotrophs) off of adjacent host trees by way of fungal connections underground. These plants are not only important to the plant diversity of sub-boreal forests, but also may turn out to be important indicators of forest health. A recent climate change-facilitated disturbance, the mountain pine beetle epidemic, has created a wonderful natural laboratory to study the interactions between these fascinating plants in the wake of the loss of many of their tree hosts.