| 概要 |
2つの異なった植栽形式,すなわち,単植と巣植の場合のスギの成長,生態を幼令林と壮令林で比較した結果次のことが判った。1.幼令林の場合,生存率は巣植の方が単植よりも高かった。壮令林については最初の値栽本数が不明なためはっきりしなかった。2.樹高成長は幼令林においては巣植と単植との間に差はみられなかったが,壮令林では巣植の方が高かった。3.幼令林の根元直径は単植の方が巣植よりも大きかった。壮令林の胸高...直径は樹高と同じく巣植の方が単植よりも大であった。4.形状比は幼令林では巣植の方が高かったが,壮令林では巣植の方が低かった。5.幼令林の樹高,根元直径の度数分布には個体相互のせりあいの影響は現れていない。また,壮令林の胸高直径の度数分布にもそれは現れていない。6.幼令時の樹冠,根系の発達には個体相互のせりあいの影響がみられた。7.幼令林の成長結果から,雑草木との競合下では巣植の方が単植に比し,雑草木に対し抵抗性があり,より良い成長を示すのではないかと想定された。8.壮令林の場合,単植に比較して巣植の成長がよいことは,その樹冠の受光面積が大であることと密接な関係があるようである。
This paper deals with the study of influences of differences of planting densities and types on the growths of young Sugi stand (Stand I) and adult stand (Stand II). The former stand was established in March 1958 and the latter in 1933. The planting types were planting by individuals (Type A) and planting in clumps (Type B), were the number of trees per clump was from 2 to 6. The results obtained are summarized as follows. 1. In Stand I, the survival ratio of Type B was higher than that of Type A. 2. In Stand I, the height growths were not affected by differences of densities or types. But in Stand II, the height growths of Type B were higher than those of Type A. 3. In Stand I, the diameter growths at the ground level of Type A was larger than those of Type B. In Stand II, the diameter growths at the breast height of Type B was larger than those of Type A. 4. The form quotient (height/diameter) of Type A was higher than that of Type B in Stand I. On the other hand, the relationship was reverse in Stand II. 5. The frequencies of height and diameter at the ground level in Stand I and of diameter at the breast height in Stand II had not been affected by competition among individuals. 6. The development of crowns and root systems had been affected by competition among individuals. 7. The growth of Stand I showed that Type B was in a more advantageous position as to the competition with weeds and shrubs. 8. In Stand II, Type B showed better growths than Type A. It seems that the better growths of Type B was related to the fact that Type B had larger surface of the sunny crown than Type A.続きを見る
|
Mendeley出力
KJ00005470452