Background & Rationale
Yukon has experienced rapid anthropogenic climate change in recent decades (IPCC 2013), and observed climate trends for the Yukon are pointing to an increasingly warmer climate without a commensurate increase in moisture (Mbogga et al 2009). Climate-induced changes to ecological communities depend on the capacity of species to tolerate and adapt to new environments, and it is generally difficult to predict how much disturbance an ecosystem can absorb before it is pushed into a different ecological state.
The influence of climate change on forested ecosystems is a manifestation of changes to several ecological processes operating at multiple temporal and spatial scales. Bioclimate envelope modelling is arguably effective at predicting biological potential using the known relationship of ecosystems and their associated climate. Ecological response on mesic (or average) sites, is typically driven by broad climate conditions, and therefore likely
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well predictable by models that project the distribution of climatically suitable ecosystems.
Such models can also be used to explore how climatic factors - driving biological potential - may shift with projected climate change. A bioclimatic framework – coupled with climate change modelling - can be used to optimize the design of climate change monitoring/research programs to detect indicators of change and assess degree of resilience at the local to regional scale.
A bioclimatic envelope approach to assess ecological change has been used to study boreal ecosystem response to climate change (Fettig et al. 2013; Mahony et al 2017; Mbogga et al 2010; Rehfeldt et al 2012; Wang et al 2012). However these approaches have not incorporated bioclimatic zones in Yukon that reflect altitudal climatic zones.
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Research Objectives
In this study I ask how the biological potential of Yukon’s boreal forest has shifted over the last 55 years given climate change. To address the question, I (1) will develop and test a bioclimate model and (2) use this model to project climate change impacts on the distribution of bioclimate envelopes at a regional scale. Using assembled data sources and climate change projections, I ask two questions: 1) What are the climatic variables that separate bioclimate zones, and 2) and has the distribution of these climate zones changed in recent years?
Understanding the linkages between biological potential and realized ecological systems will provide insight into an ecosystem’s ability to persist over a range of climatic conditions. Interpretation of projected bioclimate envelopes will provide guidance to Yukon land managers to design climate change monitoring/research programs.
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There are two narratives that describe patterns of climate change in Yukon. First, the Yukon is getting warmer and secondly, higher elevation landscapes are changing more quickly than lower elevation. I expect that overall, when considering Yukon as a whole it will be trending towards a warmer climate. I also expect to observe that rate of climate change will increase along an altitudinal and latitudinal gradient as a general pattern across the Territory. I expect however that climate change across the Yukon will not be homogeneous. Yukon climate is influenced by arctic, maritime and continental global climate regimes that will interact in unexpected ways. I expect that some regions of Yukon will defy or delay climate change or show a trend that is in opposition to the broader trend at a territorial scale.
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To learn more...
This video was produced in collaboration with Yukon government's Climate Change Secretariat. It highlights the use of an ecological classification system that incorporates climatic factors - making it useful to link ecological response to climate change.