[A-HW27] Biodiversity, nutrients and other materials in ecosystems from headwaters to coasts

[AHW27-14] Soil moisture and thermal regime in a forest in the Hokuriku region

*Masahiro Kobayashi¹, Yuko Itoh¹, Akira Ogura² (1.Forestry and Forest Products Research Institute, 2.Ishikawa Agriculture and Forestry Research Center)

Keywords:Hokuriku, Forest soil, moisture and themal regime

Moisture and thermal regime in forest soils affect the transport, storage, and transformation processes of materials. In this study, soil moisture potential and soil temperature were continuously observed in a forest in Ishikawa Prefecture, Hokuriku District, Japan, where precipitation is high throughout the year and snow accumulation and snowmelt occur simultaneously in winter.
Due to high precipitation throughout the year, the soil were tend to be kept moist, and downward hydraulic gradients were predominant, including in winter with snowfall. Water fluxes calculated by multiplying unsaturated hydraulic conductivity measured using soil samples were in good agreement with precipitation and snowmelt. In the early part of the snow season, a rapid decrease in soil temperature down to the deeper soil layers was observed, which was thought to be influenced by the infiltration of snowmelt water.