Snow ablation modelling in a mature aspen stand of the boreal forest

✍ Scribed by J. P. Hardy; R. E. Davis; R. Jordan; W. Ni; C. E. Woodcock

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 239 KB
• Volume: 12
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/(sici)1099-1085(199808/09)12:10/11<1763::aid-hyp693>3.0.co;2-t

✦ Synopsis

Snow ablation modelling at the stand scale must account for the variability in snow cover and the large variations of components of energy transfer at the forest ¯oor. Our previous work successfully predicted snow ablation in a mature jack pine stand by using a one-dimensional snow process model and models predicting radiation below forest canopies. This work represents a second test of our basic modelling scenario by predicting snow ablation in a lea¯ess, deciduous aspen stand and verifying the results with ®eld data. New modi®cations to the snow model accounted for decreased albedo owing to radiation penetration through optically thin snowpacks. A provisional equation estimates litter fall on the snowpack, thereby reducing the areal averaged albedo. We showed that subcanopy radiation measurements can be used with a canopy model to estimate a branch area index for defoliated aspen as an analogue to the foliage area index used for conifers. Modelled incoming solar and long-wave radiation showed a strong correlation with measurements, with r 2 0 . 96 and 0 . 91 for solar and long-wave radiation, respectively. Model results demonstrate that net radiation overwhelms turbulent exchanges as the most signi®cant driving force for snowmelt in aspen forests. Predicted snow ablation in the aspen stand compared very favourably with available data on snow depth.