The relationship of soil temperature to vegetation height

Using extensive observations of air and soil temperatures made under a variety of vegetated surfaces (forest, heather and grass) the influence of vegetation characteristics on the mean soil temperature is considered. It is demonstrated that the main influence is the height of the vegetation, with canopy density only a subsidiary factor. Consideration of the energy balance from two catchments in Wales (one forested and one grassland) strongly suggests that it is the aerodynamic resistance (itself related to vegetation height) which is the determining factor.