Using Individual-Based Modeling to Understand Future Climate Impacts on Canadian Aspen Parklands

Abstract:

The Aspen Parklands Ecoregion of western Canada is a transitional biome between the Prairie and Boreal Transition Ecoregions, and is experiencing shifting vegetation dynamics at an alarming rate, brought on by climate change. This ABoVE-funded research utilizes an individual-based forest model (SIBBORK-TTE) and remote sensing to investigate the effects of changing climatic conditions on the region. The Parklands have experienced recent severe droughts (1980s, early 2000s), immediately followed by increasing tent caterpillar outbreaks, resulting in weakening stands and inviting secondary damage by wood boring insects and fungal pathogens. Studies have shown that the climate in this region is shifting toward being increasingly limited by moisture. The region experiences earlier springs thus increasing productivity earlier in the year, which tends to result in drought stress and lower productivity later in the year. Using the Climate Impacts on Productivity and Health of Aspen (CIPHA) dataset collected by the Canadian Forest Service, we parameterized and tested the SIBBORK-TTE model for Aspen Parklands. We then updated specific plant and stressor parameters at individual CIPHA nodestands and simulated CMIP6 future climate scenarios. Here we present results of initial model testing, subsequent statistical analysis conducted on model output after adjusting stress and mortality functions, and future climate scenario impacts. Our study indicates that shifting seasonality and climate are adversely impacting Aspen Parklands and highlights the use of individual-based gap models for investigating complex feedback relating drought, mortality and climate.