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    Dr. Alan Barr

    Environment and Climate Change Canada

      Research areas

      1. Contributed to the Ireson et al. (2015) synthesis paper, which provided an interdisciplinary review of the changing water cycle in the Boreal Plains Ecozone of Western Canada. The paper: reviewed the connections among climate, hydrology and ecology under a changing climate; explored ways that hydrological processes determine ecosystem functioning; and identified critical knowledge gaps, including how our ability to predict system response is limited by our ability to predict hydrologic change.
      2. Collaborated with CCRN and external partners on studies that utilized the BERMS data sets (see Publications below). The most significant findings were:
        1. a global relationship between boreal carbon uptake and snowmelt timing (Pulliainen et al., 2017);
        2. a large annual carbon loss following defoliation of a boreal aspen forest by forest tent caterpillar (Stephens et al., 2018);
        3. evaluation and development of models (Chen et al, 2016; Chun et al., 2014; He et al., 2014; Yuan et al., 2014) and remote sensing algorithms (Hopkinson et al., 2016; Middleton et al., 2016).
      3. Contributed to BERMS data management and the development of protocols for the CCRN data system.
      4. Collaborated on the evaluation of the Environment Canada CLASS and CTEM models using long-term observations from the BERMS sites (work in progress):
        1. developed a new approach for water-stress feedbacks on photosynthesis and transpiration;
        2. evaluated the CTEM competition algorithm at the prairie-forest ecotone, using flux observations at the BERMS aspen and jack pine flux towers and the AB grassland (led by Omer Yetemen);
        3. evaluated the energetics of spring snow melt and soil thaw in CLASS (with Faizan Ahmed).
      5. Worked with CCRN ecologists to develop a vegetation change scenario for MESH modelling of the Saskatchewan and Mackenzie River basins over the 21st century, based on maximum plausible vegetation changes. The scenario was developed by first deriving a change signal from the recent climate-based projections of Elizabeth Campbell (Pacific Forestry Centre), and then applying the change signal to the LLC05 base map used by MESH to model 1981-2010. The change-signal approach: anchored the projections to the observed base map and preserved the patchiness of the observed vegetation mosaic; applied expert opinion to eliminate changes that are not plausible over the modelling time frame (1981-2100); and integrated wildfire as a trigger for specific vegetation changes that occur only after disturbance. The primary changes captured in the change scenario were: the expansion of agricultural cropland into the southern boreal mixedwood forest; the replacement of patches of southern boreal evergreen forest by grassland after wildfire; the post-fire replacement of patches of evergreen forest by mixedwood forest in the central and northern boreal forest; and the expansion of shrubs above the northern and alpine treelines.