A note on vegetation temperatures above the timber line in southern Norway

Surface temperatures of dwarf shrubs and other components of Norwegian fjell vegetation were measured with an infrared thermometer of simple construction. With strong solar radiation, temperatures varied between 2°C (cold spring) and 63 °C (ant hill). Dwarf shrubs like Loiseleuria had temperatures up to 20 °C above air temperature. From heat budget considerations the conclusion is drawn that the fjell vegetation transpires rather slowly and transforms most of the absorbed energy into heat. The possible importance of the high vegetation temperatures is discussed.