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

点击翻译按钮获取中文摘要

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.