• Journal of Korean Society of Forest Science
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• v.113 no.1
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• pp.66-72
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• 2024

Determining the nutrient stoichiometry in plant organs is critical for understanding nutrient uptake and cycling in forest ecosystems. This study evaluated nutrient concentrations and stoichiometry in various plant organs (stem, bark, branches, and foliage) of species found in four warm-temperate forests in southern Korea. Cryptomeria japonica D. Don (CJ), Quercus serrata Thunb. (QS), evergreen broadleaved tree species (EB), and bamboo spp. (BB) were destructively sampled to measure nutrient (C, N, and P) concentrations in the plant organs. The mean C concentration in the stem was significantly higher in CJ than in QS, BB, or EB, whereas the C concentration in the foliage was the lowest in BB. The mean foliar N and P concentrations were higher in BB than in EB or CJ. The mean stem C:N and C:P ratios were highest in CJ but were lowest in the foliage of BB. Overall, stems of all species showed a strong positive correlation between C concentration and dry weight, but a negative correlation between N and dry weight. The N and P concentrations of foliage and bark were strongly correlated, whereas those of the stem and branches were poorly correlated. Positive correlations were detected between the C:N and C:P ratios in bark and foliage. These results indicate the existence of intraspecific differences in nutrient requirements in warm-temperate forest species and add to the understanding of nutrient uptake and storage patterns in the organs of species growing in warm-temperate forests.

• Korean Journal of Environment and Ecology
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• v.21 no.2
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• pp.113-119
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• 2007

To investigate the vegetation structure at Orimok of Hallasan national park, 28 plots$(2,000m^2)$ were surveyed by random sampling method. Carpinus tschonoskii was a major woody species in the studied area in Orimok, and Quercus gorsseserrata, Quercus serrata, and Quercus mongolica were partly occupied. High negative correlations were shown between C. tschonoskii and Ilex macropoda, Lindera erythrocarpa, Quercus mongolica Comus walteri and Symplocos coreana, and relatively high positive correlations were proved to exist between Acer pictum var. mono and Carpinus cordata, Quercus gorsseserrata Ilex macropoda and Lindera erythrocaypa, Q. mongolica Abies nephrolepis and Prunus sargentii, Kalopanax septemlobus Taxus cuspidata and Symplocos coreana. Species diversity(H') was 0.771, and it was relatively low numerical value compared to that of other national parks.

• Korean Journal of Environment and Ecology
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• v.21 no.2
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• pp.161-167
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• 2007

To investigate the structure and the conservation strategy of Korean native species, the Abies koreana forest at sub-alpine zone centering on the Witsaeorum(1,714m) shelter in Hallasan National Park was selected for a survey subject with 20 plots $(10{\times}10m)$ set up with random sampling method. Mean importance percent(MIP) of Abies koreana showed the highest numerical value-57.7%, and that of faxus cuspidata was the next value-16.2%. High positive correlations were shown between Taxus cuspidata and Prunus maximowiczii, Euonymus alatus; Betula ermani and Berberis amurensis var. quelpaertensis, Prunus sargentii; Prunus maximowiczii and Euonymus alatus; Berberis amurensis var. quelpaertensis and Prunus sargentii. Vigor of Abies koreana was so low that as much as 6.44% of total number of Abies Koreana investigated were dead. DBH of dead individuals ranged mainly from 5cm to 15cm.

• Korean Journal of Environment and Ecology
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• v.12 no.1
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• pp.1-8
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• 1998

To investigate the structure and the conservation strategy of Taxus cuspidata forest at Janggunbong area in Taebaeksan, 18 plots(20m$\times $20m) set up with random sampling method were surveyed. Major woody species growing with Taxus cuspidata were Acer pseudo- sieboldianum, Euonymus macroptera, Prunus padus, Abies nephrolepis. High positive correlations was proved between abies nephrolepis and Pinus doraiensis, Betula ermanii and Magnolia sieboldii, and high negative correlations was proved between Acer pseudo- sieboldianum and Tripterygium regelii, Weigela subsessilis and Acer tschonoskii var. rubripes, Taxus cuspidata and Acer tschonoskii var. rubripes. Species diversity(H') of investigated area was calculated 2.3015(0.9991) and this value was relatively lower than that of other subalpine forest. Taxus cuspidata trees were severely stressed and vigor-lossed and 8.22% of surveyed Tacus cuspidata trees were dead tree. Dead trees were distributed mainly in 20~60cm DBH class and a few seedlings of Taxus cuspidata were observed. To conserve Taxus cuspidata forest at Janggunbong area in Taebaeksan, intensive research, prescription on the decline of Taxus cuspidata and proper forest management were needed.

• The Korean Journal of Malacology
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• v.32 no.4
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• pp.289-295
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• 2016

Study on characteristics of the molluscan community structure and relationship between the structure and environmental variables in the abyssal plain of the East Sea was carried out for 5 years, starting from 2009 until the end of 2015 except 2010 and 2011. The water depth at the study site is approximately 1,600 m at minimum, and maximum depth of 2,000 m and a total of 16 molluscan species including Aplacophora, Gastropoda and Bivalvia were observed. Species with the highest biomass was Thyasira tokunagai, followed by Yoldiella philippiana which were observed at 9 sampling stations every year. Among 4 sampling stations having various depths (1,600/ 1,700/ 1,800/ 2,000 m), the highest diversity for species was observed at water depths of 1,600 m and 1,700 m, but found the lowest at 1,800 m. Both abundance and biomass were found to be negative correlations with water depth (p < 0.05), however, showed a positive correlation with the concentrations of organic matters (p < 0.01, p < 0.05). However, it is interesting to note that both Thyasira tokunagai (biomass, 82.6%; abundance, 44.1%) and Yoldiella philippiana (biomass, 15.9%; abundance, 4.7%) did not show distinctive correlations with water depth as well as concentrations of organic matters (p > 0.05). Therefore, it could be concluded that community structure of both Thyasira tokunagai and Yoldiella philippiana did not appear to be affected by water depth and concentrations of organic matters but geographical characteristics.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.11
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• pp.1513-1522
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• 2000

In this study, the burning velocities of LFG and LFG mixed fuels have been numerically determined. C3 reaction mechanism involving 92 species and 621 reactions was adopted in the calculation. The computed burning velocities using C3 mechanism show good agreements with experimental data. Based on numerical results, the maximum burning velocities of LFG and LFG mixed fuels were correlated as a function of CH$_4$ and LFG component percentage at stoichiometric conditions. In addition, the correlations of burning velocities of LFG and LFG mixed fuels were obtained over a wide range of the equivalence ratio. The numerical results are well agreed with the burning velocity correlations. The burning velocity correlations for LFG and LFG mixed fuels suggested in this study can be applied to the practical utilization of LFG.

• Genomics & Informatics
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• v.1 no.2
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• pp.87-93
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• 2003

DNA microarray is currently the most prominent tool for investigating large-scale gene expression data. Different algorithms for measuring gene expression levels from scanned images of microarray experiments may significantly impact the following steps of functional genomic analyses. $Affymetrix^{(R)}$ recently introduced high-density microarrays and new statistical algorithms in Microarray Suit (MAS) version 5.0$^{(R)}$. Very high correlations (0.92 - 0.97) between the new algorithms and the old algorithms (MAS 4.0) across several species and conditions were reported. We found that the column-wise array correlations had a tendency to be much higher than the row-wise gene correlations, which may be much more meaningful in the following higher-order data analyses including clustering and pattern analyses. In this paper, not only the detailed comparison of the two sets of algorithms is illustrated, but the impact of the introducing new algorithms on the further clustering analysis of microarray data and of possible pitfalls in mixing the old and the new algorithms were also described.

• Korean Journal of Ecology and Environment
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• v.47 no.4
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• pp.247-257
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• 2014

The construction of eight large weirs in the Nakdong River, Korea, caused a decrease in the water flow velocity and several physical changes to the water environment. Here, changes in phyto- and zooplankton communities and water quality in the areas near the eight weirs were investigated from 2011 to 2013, and relationships between phytoplankton abundances and environmental factors were analyzed. Special emphasis was given to the succession patterns in algal abundance based on temperature fluctuations. At the eight weirs, 24 dominant species were found. The most abundant phytoplankton species was Stephanodiscus sp. (39.4% of dominant frequency). Cyanobacteria of the genus Microcystis dominated during the summer, with an dominant frequency of 8.5% and cell abundance ratio of 36.6%. Significant correlations were observed between temperature and abundance of eight of the main dominant species; seven species showed positive correlations with temperature. Stephanodiscus sp., however, showed a negative correlation with temperature (r=-0.26, p<0.01). In addition, this species showed a significant negative correlation with the dominant algal species-Aulacoseira granulata and Aphanizomenon flos-aquae, with the zooplankton Copepoda and with Cladocera. On the contrary, seven other dominant species of algae showed significant positive correlations with zooplankton. Thus, we showed that the seasonal succession of plankton communities in the Nakdong River was related to the water temperature changes.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.906-912
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• 2000

In this study, for the use of LFG, the burning velocities of LFG and LFG mixed fuels have been numerically analyzed. C3 reaction mechanism which consists of 92 species and 621 reaction was adopted in the calculation. The results show that the burning velocities of LFG and LFG mixed fuels are obtained as a function of $CH_4$ and LFG percentage at stoichiometric conditions. In addition, the correlations of burning velocities LFG and LFG mixed fuels were obtained over a wide range of the equivalence ratio. The comparison of burning velocity correlated from numerically calculated results with experimental ones shows good agreements. From these results, the suggested burning velocity correlations far LFG and LFG mixed fuels in this study can be applied to the practical utilization of LFG.

• Korean Journal of Environmental Biology
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• v.27 no.3
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• pp.314-322
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• 2009

Vegetation, environmental characteristics and soil analysis of Megaleranthis saniculifolia Ohwi habitats were investigated to propose the basal data for conservation and restoration. M. saniculifolia was distributed around an altitude of 770~1,440 m with an inclination of $0{\sim}20^{\circ}$, and mostly formed discontinuous populations in northern part of valley. The vascular plants from 78 quadrates of 11 habitats were identified 111 taxa. Importance value of M. saniculifolia was 27.05%, and highly ranked 5 species such as Veratrum oxysepalum (5.67%), Corydalis turtschaninovii (5.32%), Aruncus dioicus var. kamtschaticus (4.35%), Meehania urticifolia (4.06%) and Anemone koraiensis (3.91%) were considered to be an affinity with M. saniculifolia. Dominant species of woody plants in 78 quadrates were represented as Cornus controversa, Juglans mandshurica, Quercus mongolica, Acer pseudo-sieboldianum and A. mono in tree (B1) layer, A. pseudo-sieboldianum and Carpinus cordata in subtree (B2) layer, Deutzia glabrata and Prunus padus in shrub (S) layer. Average species diversity was 1.16, and dominance and evenness were found to be 0.12 and 0.81, respectively. Average field capacity was 26.41%, and the organic matter and soil pH were 7.83% and 5.83. Correlation coefficients based on environmental factors, vegetation and soil analysis were showed that the positive correlations between slope degrees and pH, slope degrees and organic matter, dominance and importance value, species diversity and richness, whereas between species diversity and dominance, and importance value and dominance were showed negative correlations.