Meta-analysis of Regional Characteristics on Differences of Snow Disappearance Dates Between Open and Forest Areas

Abstract

Understanding the relation between forests and snow, including determinants of differences in the snow disappearance date between open and forested areas, is fundamentally important for assessing the ability of forests to store snow and to delay snowmelt. For this study, using a meta-analysis, we analyzed factors that determine the difference in snow disappearance date (ΔSDD) between open and forested areas, where positive (negative) values indicate whether the snow cover in the forest (open) remains longer. Results indicate that ΔSDD was mostly distributed in the period from 0 to +10 days, with a mean of +6 days. Negative correlation was found between ΔSDD and mean winter temperature. Relation between ΔSDD and mean winter temperature on a global scale was compared to that of Japan, where results showed that ΔSDD can be either positive or negative. Compared to the same temperature zone on a global scale, the snow storage functions of forest areas are demonstrated well in Japan, but these might decline in the future. In addition to ΔSDD, using the ratio of the snow water equivalent in the forest to that in the open (coefficient a) is important. The ratio of the average snowmelt rate in the forest to that in the open (coefficient b), is also important when comparing the snow storage functions of forests.