NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region

Tags: active layer, permafrost, vegetation, climate change, carbon, boreal forests, soil moisture, nitrogen, tree ecology

Objective(s): To understand the extent to which nutrients will limit forest growth and terrestrial carbon sequestration in Canadian boreal forests and to improve how this is represented in climate change models. Specifically, to characterise nutrient limitation of forest growth across the Canadian boreal forest at the southern and northern limits, focusing on nitrogen.

Project Description: This licence has been issued for the scientific research application No. 6084. The overarching objective of this research is to understand the extent to which nutrients will limit forest growth and terrestrial carbon sequestration in Canadian boreal forests and to improve how this is represented in climate change models. These climate change models can then be used to understand the impacts of climate change on Canadian boreal forests over the 21st century. This is an important knowledge gap both for understanding of Canadian boreal forests and for climate change projections. Specifically, this research will characterise the degree of nutrient limitation of forest growth across the Canadian boreal forest at the southern and northern limits, focusing on nitrogen, an essential limiting nutrient to forest growth. This information will improve the representation of nutrient cycling in the Environment and Climate Change Canada (ECCC) climate change model. The ECCC climate change model will then be used to understand how climate change will impact Canadian boreal forests and how this in turn will feed back to climate change itself over the 21st century. This work will be conducted in collaboration with and will build on established research at the Trail Valley Creek and Havikpak Creek Research Stations (Drs. Phil Marsh and Oliver Sonnentag). Research will be conducted at the Trail Valley Creek and Havikpak Creek Research Stations. Small samples of tree leaf and tree stem (< 5g) will be taken, focusing on black spruce and green alder. Small samples of soils adjacent to these trees (< 5g) will also be taken. The carbon and nitrogen contents of these samples will be measured in addition to photosynthesis rates, growth rates, and soil decomposition rates. These measurements will be repeated annually for 5 years (ideally, in continuity) to understand immediate climate change impacts. These measurements will also be conducted at the southern limit of the Canadian boreal forest in Saskatchewan. These data will be used to characterise the degree of nutrient limitation of forest growth as well as how it varies across a latitudinal/temperature gradient representative of Canadian boreal forests. These data will then be used (alongside the comprehensive biometeorological data being collected at these sites) to evaluate and improve the ECCC climate change model. More detailed information is given in the Supporting Documentation. We will build on the communication avenues established by researchers at the Trail Valley Creek and Havikpak Creek Research Stations. After data collection (in Years 2-5), we intend to write a report on our research findings that will be shared directly with communities on an annual basis. We would also like to share this research via a public lecture in the Speaker Series at Aurora Research Institute. This would include information on how this research directly relates to climate change projections for Canada’s North over the 21st century. The fieldwork for this study will be conducted from: May 01 - August 31, 2025