The Role of Willow-Birch Forest in the Surface Energy Balance at Arctic Treeline
Blanken PD and Rouse WR. 1994. The Role of Willow-Birch Forest in the Surface Energy Balance at Arctic Treeline. Arctic and Alpine Research. 26(4):403-411
Continuous measurements of the energy balance components were made during the 1991 growing season over a willow-birch forest located near Churchill, Manitoba, Canada. On the basis of measurements of leaf area index, the growing season was divided into three distinct periods: growth, mature, and senescence. Changes in surface albedo were strongly correlated with changing leaf area index during the growth period with albedo increasing as leaf area increased. The latent heat flux density, QE represented 74% of net radiation during the mature period compared to 55 and 54% during the growth and senescence periods, respectively. The greater QE at plant maturity is due primarily to canopy transpiration. The sensitivity of QE to net radiation was largest during the growth period. In contrast, the sensitivity of QE to the surface resistance and aerodynamic resistance was largest during the mature period. The implications of climatic variability on the timing of leaf development and the surface energy and water balance are discussed.
- Type
- Journal Article
- Authors
- Blanken, Peter; Rouse, Wayne
- Units
- ARCN , BELA , CAKR , GAAR , KOVA , NOAT
- Keywords
- Arctic, Canada, Climate, Flux, Impacts, Sensitivity, Tundra, Wetland