• Journal of Korean Society of Forest Science
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• v.4 no.1
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• pp.24-25
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• 1965

A statistical study was made on the size of sample plot to be used in the preparation of a yield table. This has always been an important problem needing solution in Korea. For this purpose, 3 replications of Korean white pine plantings with block size of $80m{\times}80m$ were established in the Kwangneung Experimental Forest. A location map was prepared of the pines in the blocks and the heights and the breast height diameters measured. Then those blocks were divided into 64, 64, 16, 16, 4, 4, and 1 standed $40m{\times}80m$ and $80m{\times}80m$ each. After these divisions, the average heights, average breast height diameters, standard deviations and coefficient of variations were computed for the plots and averaged according to plot size. As the results of these computations, it was shown that the standard deviation and the coefficient of variation suddenly increased with the beginning of an increase in plot size. However, these indicated an approximately constant value at a certain limit. Although the average value decreases with the initial increase in plot size, it also indicates an approximately constant value at a certain limit. This limit was between $20m{\times}40m$ and $40m{\times}40m$. With the purpose of evaluating these facts, the average height and the average diameter were computed for the number of standing trees in the $10m{\times}10m$ plots. A negative (minus) relationship was found between the number of standing trees and the average value. As a result of above evaluation, it was found that when the size of plot area was small, a larger estimated value, was obtained as well as a smaller standard deviation and coefficient of variation. It is possible, therefore, that an incorrect value might be used in the evalution of data as the stand structure could appear to be uniform when the plot size was small. In general, when the size of plot area is larger than $40m{\times}40m$, the probability of the difficulty occurring mentioned above is estimated to be small.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.4
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• pp.290-295
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• 1994

Soil $CO_2$ evolution was measured using the soda-lime method for 20-year-old L. tulipifera, P. albaglandulosa, and Q. rubra plantations planted on a similar soil type in the Kwangneung Experimental Forest during the growing season of 1994. Soil $CO_2$ evolution ranged from $0.21g/m^2/hr$ for Q. rubra to $0.33g/m^2/hr$ for L. tulipifera. and was significantly different among species. We found positive correlations between soil $CO_2$ evolution and air(p<0.001, r=0.39) and soil temperatures(p<0.001, r=0.49). Peaks in seasonal soil $CO_2$ evolution occurred in July and August. Seasonal soil $CO_2$evolution did not necessarily follow changes in air and soil temperatures. This study implies that more work is needed to clarify the influence of other factors on soil $CO_2$evolution.

• Korean Journal of Environment and Ecology
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• v.31 no.6
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• pp.508-519
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• 2017

There have been many studies on monitoring of biodiversity changes and preservation of Gwangneung Forest Biosphere Reserve (GFBR) in South Korea in recognition of the rare ecosystem that has been preserved for a long period. However, there are few studies on diversity and community characteristics of benthic macroinvertebrates as an indicator of stream health of GFBR. The purpose of this study was to assess the water quality of Bongseonsa Stream that penetrated through Gwangneung Forest and the nearby torrents by analyzing the benthic macroinvertebrates community during April to September 2016. The investigation collected a total of 114 species of benthic macroinvertebrates belonging to 56 families, 17 orders, 8 classes, and 5 phyla from the Bongseonsa Stream and Kwangneung Stream. Ephemeroptera and Trichoptera were the largest groups in species diversity with 30 species (32.3%) and 16 species (17.2%), respectively, and Tubificidae sp., Baetis fuscatus, Antocha KUa, and Cheumatopsyche brevilineata, which usually habit in contaminated streams, appeared frequently. Among the feeding function groups, the gatherers and hunters appeared relatively frequently, and the shredders and scrapers appeared frequently in the torrents. Among the habitat oriented groups, the clingers and burrower appeared more frequently and represented the microhabitats in the shallow areas. The result of the analysis of benthic macroinvertebrates community showed that the dominant index was $0.48{\pm}0.10$ in average while it was lowest with 0.33 in GS 8 of the Gwangneung Forest torrent and highest in BS 1 of Bongseonsa Stream. The diversity and richness indices were inversely proportional to the dominant index and were 2.53 and 4.22, respectively, in GS 8 where the dominant index was low. The result of the analysis of community stability showed that area I, which had high resistance and restoration, was high in Bongseonsa Stream while the area III, which had low resistance and restoration, was high in Gwangneung Forest, indicating that the water system in Gwangneung Forest had a wider distribution of specifies sensitive to agitation. The biological water quality assessment showed ESB of $50.88{\pm}17.69$, KSI of $1.11{\pm}0.57$, and BMI of $78.55{\pm}11.05$. GS 8 of Gwangneung Forest torrent was judged to be the highest priority protective water area with the best water environment and I class water quality with ESB of 63, KSI of 0.55, and BMI of 89.9. On the contrary, BS 1 of Bongseonsa Stream was judged to be the high priority improvement area that had the lowest water quality rating of III with ESB of 25, KSI of 2.13, and BMI of 62.7. Although the diversity of water beetle was higher in the water system of nearby Bongseonsa Stream than the water system inside the Gwangneung Forest, the annual community structure appeared to have distinct differences.