Seasonal changes in soil temperature on an upper windy ridge and lower leeward slope in Pinus pumila scrub on Mt. Shogigashira, central Japan

• Main Author: Koichi Takahashi
• Format: Report
• Language: English
• Published: Department of Biology, Faculty of Science, Shinshu University 2005
• Subjects: alpine zone; Pinus pumila; seasonal change; soil temperature; Polar bioscience
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=6228; http://id.nii.ac.jp/1291/00006228/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=6228&item_no=1&attribute_id=18&file_no=1

The seasonal changes in soil temperature at 5 cm below the surface were monitored on an upper windy ridge (2675 m a.s.l.) and lower leeward slope (2640 m a.s.l.) in Pinus pumila scrub on Mt. Shogigashira in central Japan, from October 2001 to September 2002. The scrub heights were ca. 20 cm and 100 cm on the upper windy ridge and lower leeward slope, respectively. The soil temperature on the upper windy ridge decreased from the autumn to mid-February and increased thenceforth. The soil temperature was sometimes lower than -10°C in winter. In contrast, the soil temperature on the lower leeward slope was relatively stable at about -1°C during the winter. It appears that accumulation of snow prevented cooling of the soil surface. In the snow-free period, the daily maximum soil-temperature was higher on the upper windy ridge than on the lower leeward slope. This difference was evident in May after the snowmelt, and decreased gradually toward the autumn. The solar radiation was highest at around the summer solstice. Much solar radiation penetrated to the soil surface on the upper windy ridge because of its poorly developed canopy, which increased the soil temperature. Thus, this study shows that seasonal changes in soil temperature are different between the upper windy ridge and lower leeward slope due to snow accumulation, canopy development and seasonal changes in solar radiation.