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Identifying historical climate-growth limitations of white spruce (Picea glauca) populations across North America
- Author / Creator
- Hynes, Ashley
Climate change may cause reduced forest productivity and higher tree mortality due to water deficits that result from increased evapotranspiration. Such limitations may occur in some areas of the North American boreal forest, where precipitation is low and warming trends are high. This thesis analyzes the climatic factors that limit the growth of a commercially important and widespread boreal tree species, white spruce (Picea glauca (Moench) Voss), based on a
range-wide dendroclimatological analysis of 9795 trees from 227 sample sites across the North American boreal forest. A bootstrapped response function analysis was conducted for
monthly temperature and precipitation variables, and a multivariate regression tree analysis was used to group white spruce populations with similar response coefficients, where
climatic factors explained 46% of the total variance in response coefficients. The results of this study shows that white spruce populations in the west-central boreal forest of North America are the most precipitation-limited group and therefore likely to be most susceptible to climate change. Populations both to the north and south of this group appear less vulnerable, and eastern populations generally do not experience growth-limiting moisture deficits. Given regional climate change projections, it is possible that declines of white spruce in the southwest and west-central boreal forest may be inevitable.
- Graduation date
- Spring 2021
- Type of Item
- Master of Science
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.