Received: 1 September 2020 Revised: 29 March 2021 Accepted: 30 March 2021 DOI: 10.1002/hyp.14158 RESEARCH ARTICLE Subalpine forest water use behaviour and evapotranspiration during two hydrologically contrasting growing seasons in the Canadian Rockies Lindsey E. Langs1,2 | Richard M. Petrone1 | John W. Pomeroy2 1Hydrometeorology Research Group, Department of Geography and Environmental Abstract Management, University of Waterloo, Hydrological processes in mountain headwater basins are changing as climate and Waterloo, Ontario, Canada vegetation change. Interactions between hydrological processes and subalpine forest 2Centre for Hydrology, University of Saskatchewan, Canmore, Alberta, Canada ecological function are important to mountain water supplies due to their control on evapotranspiration (ET). Improved understanding of the sensitivity of these interac- Correspondence Richard M. Petrone, Hydrometeorology tions to seasonal and interannual changes in snowmelt and summer rainfall is needed Research Group, Department of Geography as these interactions can impact forest growth, succession, health, and susceptibility and Environmental Management, University of Waterloo, Waterloo, ON, Canada N2L 3G1. to wildfire. To better understand this sensitivity, this research examined ET for a sub- Email:
[email protected] alpine forest in the Canadian Rockies over two contrasting growing seasons and Funding information quantified the contribution of transpiration (T) from the younger tree population to Alberta Innovates - Energy and Environment overall stand ET. The younger population was focused on to permit examination of Solutions, Grant/Award Numbers: 2335 20007947, 2347; Canadian Natural Science trees that have grown under the effect of recent climate change and will contribute and Engineering Research Council (NSERC), to treeline migration, and subalpine forest densification and succession.