Changes of spatial dispersion in trees with similar sizes were analyzed during the development of an Abies sachalinensis MAst. stand. In a 20-year-old stand, just after canopy closure, trees belonging to the largest and smallest size classes were segregated. These size classes also had aggregated distributions 25 years after planting, although the degrees of aggregation were lower than those at 20 years. At 30 years, trees of the same size classes had random dispersions. At 40 and 50 years, trees in the same size classes were distributed evenly. These changes of the spatial dispersion of trees with stand age are discussed with reference to the following phases of interactions among trees, that is, non-interaction, cooperative interaction, and competitive interaction. At the time of canopy closure, the smaller trees had the greater relative diameter growth rate (RDGR) and represented an aggregated spatial distribution, suggesting cooperative interaction. Because the large trees having a larger RDGR in a further stage of forest development, smaller trees near the large ones were suppressed, suggesting the competitive interaction. Therefore at this stage, large trees were distributed randomly or evenly.
|Number of pages||7|
|Journal||THE JOURNAL OF THE JAPANESE FORESTRY SOCIETY|
|Publication status||Published - 1987 Jan 1|
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