ABSTRACT
Soil temperature directly influences tree root growth and water uptake. In addition, soil temperature affects, for example, microbial activity, nitrogen mineralization, and decomposition processes. Peat is a substrate with high porosity and naturally high water retention capacity. Wet peat has a heat capacity almost equal to that of water. When dried, the heat capacity of peat decreases to a level close to that of mineral soils, and its thermal conductivity decreases as well. The chapter investigates the relationship between the groundwater table (GWT) depth and the peat temperature and its variation during the growing season on a drained peatland site. In order to monitor the GWT depth, a systematic network of wells was established across a drainage strip in 1991. The GWT depth was expected to be influenced by the distance to the nearest ditch and, to some extent, by stand density.
