The distribution and stand structure of the natural Japanese red pine(Pinus densiflora S. et Z.) were studied in deciduous broad-leaved forests of Shimane University Forest at Sanbe.
1. The natural Japanese red pine was distributed in narrow belt on the branch ridge or in groups at the crossing point of the ridge.
2. The percentages of numbers of the natural Japanese red pine were 11.6-46.3% and those of basal area at breast height were 48.3-89.0%. Total rates of red pine and Quercus serrata were very large as 73.4-93.9%.
3. The diameter and tree height of the natural Japanese red pine were larger than those of deciduous broad-leaved trees. The relation between D and H was expressed by the following equation;
1/H = 0.53889/D + 0.03746
In deciduous broad-leaved forests mixed with the natural Japanese red pine, red pine occupied to the upper layer and Quercus serrata occupied to the middle layer.
4. The pattern of the distribution of all trees was random distribution in every plot, but the natural Japanese red pine showed the contagious distribution in the plot which the density of red pine was comparatively low.