アカマツ・クロマツ巣植の一事例

The study was made on the effect of the "nest-planting" (Planting in small groups) to the growth of Akamatsu (Pinus densiflora) and Kuromatsu (Pinus Thunbergii). Seedlings of 2 year old of these pines were planted in Dec. 1953 at the Experimental Forest of Shimane Agr. Coll. on the foot of Mt. Sanbe, dividing in following 3 plots.
Plot 1. Control planting. 1.8 × 1.4m. 123 trees.
Plot 2. Wide nest planting. Each nest consists of 5 trees
located at the corner and the center of 1 × 1m square, distance between the center of each nest was 3.6m. 20 nests.
Plott 3. Narrow nest planting. Same as plot 2, except 0.5 × 0.5 square. 10 nests.
Heights and breast height diameters of trees were measured in July 1960 and Nov. 1963. The results are as follows.
1 . The mean value of height, diameter and volume of plot 1 was the largest among 3 plots, and that of plot 3 the smallest.
2 . The results were same as 1. in the mean value of height, diameter and volume of the largest trees in each nest and in succesive 5 trees in plot 1.
3 . The decrease of growth by nest planting appeared earlier in diameter than in height.
4 . The superiority of the largest tree in the nest was not remarkable compared with that of the control planting.