To study on the annual height growth of Pinus densiflora within natural pine stands in central Korea, twenty two pure closed Pinus densiflora stands were selected subjectively in the west-central region of Korea. In each stand twenty trees were chosen randomly. For each tree, about ten to fifteen measurements of internodal lengths were made from leader top to trunk base.
A total of one hundred thirty four soil samples was collected. Each soil sample was bulked with three subsamples. The ranges of the growth measurements per stand, per tree and per otservation were 14.9-35.4㎝, 9.0㎝-54.4㎝ and 2.4㎝-69.0㎝ respectively. The total mean value was 23.5㎝. The Student-Newman-Keul´s tests for the multiple conparison among the mean values of the height growth per stand were very highly significant.
The results of the analysis of variance of the height growth data for the selected fifteen stands among the twenty two stands indicate that sampling efficiency might be increased to 744% if measurement of the growth were made on fifteen trees per stand from twenty stands instead of twenty trees per stand from fifteen stands.
The annual height growths of Pinus densiflora and Pinus koraiensis for the the period from 1960 to 1968 were 21.74±5.29㎝ (10) and 20.56±5.59㎝ (10) respectively.
The total means of easily-soluble phosphorus, total nitrogen, loss on ignition and pH for the soil samples were 2.8 ppm, 0.09%, 5.4% and 4.7 respectively. The ranges of those amounts were 18.7-1.7 ppm, 0.17-0.05%, 11.6%-3.1%, 3.9-5.1 respectively.
The relationship of the annual height growth of P. densiflora to soil was studied in terms of standard partial multiple regression. Among soil properties such as non-capillary pore space, capillary pore space, maximum field capacity, loss on ignition, soil reaction, total nitrogen and easily-soluble phosphoros investigated, the easily soluble phosphorus in one analysis and loss on ignition and soil reaction in the other analysis seem to have significant positive influence on the annual height growth.
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