Comparing Observed and Simulated Interannual Variability in the Carbon and Water Balances of the Southern Boreal Forest

English Abstract:

There is a growing realization that Earth-system models must capture the linkages between climate, hydrology and vegetation dynamics. This study will focus on the southern boreal forest of western Canada, where the forest-grassland ecotone is controlled by the water balance and is therefore sensitive to climate change. Our goal is to evaluate and improve the quantification of the structural and functional responses of the southern boreal forest plant community in CTEM (the Canadian Terrestrial Ecosystem Model), which is coupled to CLASS (the Canadian Land Surface Scheme) in the Canadian GCM (General Circulation Model) framework. The long-term detailed ecological and meteorological observations at BERMS (Boreal Ecosystem Research and Monitoring Sites) in central Saskatchewan make an excellent test bed for the ecohydrological validation of CLASS-CTEM. The initial evaluation of CLASS-CTEM will be done at stand-level, based on observations from three mature forest: aspen, black spruce and jack pine. We will focus on seasonal and interannual variability in the carbon, water and energy fluxes with particular emphasis on vegetation phenology, freeze-thaw timing and summer soil-moisture limitation. We aim to reasonably represent the seasonal phenology of different vegetation types and to capture the interannual variations in the carbon, water and energy fluxes. The modeling results will improve our understanding of the ecosystem sensitivity to climate and hydrology, with important ramifications for the sustainability of fresh water resources and wildlife habitat.