FEATURES OF SPACE DISTRIBUTION OF THE FOREST LINE AND RELATIONS BETWEEN THE FOREST LINE AND CLIMATIC LIMIT OF PERMAFROST AND CLIMATIC SNOWLINE IN CHINA

The altitude of the forest line that is generally marked by the upper limit of the dark coniferous forest zone in the vertical zones of natural vegetation is controlled by the temperatures and their annual range.In this paper, based mainly on the heights above sea level of the upper limits of the modern dark coniferous forest zones in some mountainous regions and the climatic data obtained from 102 meteorological stations in China, the theoretic altitude of the forest line has been calculated and maps showing the altitude isolines of the forest line, the isolines of height differences between the permafrost limits and the forest line and the isolines of height differences between the modern climatic snowline and the forest line in China have been constructed respectively. On that basis, the primary features of spatial distribution of the forest line in China and its relations with the permafrost limits and climatic snowline are discussed.