• Korean Journal of Ecology and Environment
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• v.47 no.2
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• pp.116-126
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• 2014

To evaluate the relationship between dynamics of Cyanobacterial bloom and rainfalls, a monthly monitoring of water quality and phytoplankton from the three serial lakes (Lake Ui-am, Lake Chung-pyeong and Lake Pal-dang) in the North Han River System were examined 12 times from May 2012 to March 2013. A dense bloom of cyanobacterium Anabaena spp., was occurred over three lakes in the summer season of 2012. In Lake Ui-am, the Anabaena population appeared in June, showed a peak in July (43,850 cells $mL^{-1}$) and disappeared in November 2012. In Lake Chung-pyeong and Lake Pal-dang, Anabaena population commonly appeared in July, showed the peaks (31,648 cells $mL^{-1}$ and 7,136 cells $mL^{-1}$, respectively) in August, and entirely disappeared in September 2012. Over the three lakes, the phytoplankton community was commonly dominated by diatoms before Monsoon, cyanobacteria during Monsoon, and diatoms after Monsoon, respectively, indicating a Monsoon-dependent succession. A correlation analysis revealed that dynamics of Anabaena population was strongly related with rainfall (r=0.72, r=0.83, r=0.88, P<0.01 for three lakes), and partly with nutrients, inflow and outflow of lakes. Therefore, this study indicates that the outbreak and destruction of Anabaena bloom in North Han River System between 2012 and 2013 was impacted by rainfalls. However, a high density of cyanobacteria in Lake Ui-am remained after Monsoon, and thus, may paroduce bad-order and toxins from phytoplankton.

• Journal of the Korean Institute of Landscape Architecture
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• v.43 no.2
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• pp.56-72
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• 2015

This study area for this research was the Taereung of the 2009 World Heritage-listed Royal Tombs of the Joseon Dynasty. The Taereung space was divided into that of the royal tomb space, religious service space, transposition space and entry space. The original vegetation is assumed to have been planted at the right, left and backside of the tomb based on historical research literature. Regarding the original vegetation landscape of Taeneung, it was assumed that Pinus densiflora was distributed around the tomb lines and tomb space, Pinus densiflora was distributed in the religion services space and transposition and Alnus japonica was distributed in the entry space. By the present status of vegetation in Taeneung, the Pinus densiflora forest was the widest area with 50.3% with the broadleaf forest at 33.7%. Quercus aliena, Quercus acutissima, and Quercus mongolica were the main species found in Taeneung. The planting area was 7.9% and Pinus densiflora were the main species planted. To analyze the plant community structure of Taeneung, 108 plots were set and divided into four spaces. The importance of the percentage of those districts was analyzed on a spatial basis and it was found that the current dominant species of the tomb space was Pinus densiflora. However, as Pinus densiflora began dying out, the power of Quercus acutissima increased and an ecological succession from the Pinus densiflora forest to Quercus aliena forest was made. In the spaces of religious services and transposition, Pinus densiflora was decreasing and Quercus spp. was expanded. In the space of entry, the dominant species were Pinus densiflora and Quercus aliena, Pinus densiflora and Quercus aliena. As soil of this area is argillaceous, Pinus densiflora is expected to disappear in the end. The prior vegetation(assumed) and present vegetation of Taeneung were compared and analyzed and a goal of vegetation management and the way in which to manage vegetation were suggested. The goal of vegetation landscape management was to analyze ecological characteristics and vegetation changes, maintain and restore a landscape suitable for historical landscape forests by space. About the space of the tomb, Pinus densiflora forests and Pinus densiflora planting zones forests should be maintained and there should be efforts to restore and manage the Pinus densiflora forests, instead of the Quercus spp. forests. About the space of religious services, Pinus densiflora forests and Pinus densiflora planting zones should be maintained and managed and there should be efforts to restore and manage Pinus densiflora forests to replace Quercus spp. Pinus densiflora forests in the space of transposition should be maintained and managed and Pinus densiflora forests should be restored to replace Quercus spp. trees. Alnus japonica forests should be restored in the space of entry.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.223-236
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• 2021

This study aims to provide basic data for the systematic conservation and efficient management of forest ecosystems by analyzing changes in understory vegetation of temperate broad-leaved deciduous forests. One-hectare permanent survey plot, consisting of 100 subplots sized 10 × 10 meters, was installed in Gwangneung forest in Pocheon, Gyeonggi-do in 2003. The state of stands and the understory vegetation in the permanent survey plot were examined at a 5-year interval from 2003 to 2018. The vascular plants found in the survey area were 56 families, 128 genera, 176 species, 18 variants, 4 varieties, and 1 subspecies, for a total of 199 taxa. The number of species in both the shrub layer and the herbaceous layer showed a tendency to decrease with time. The MRPP-tests showed a significantly differing species composition of the shrub layer in all years except 2008-2013, whereas significant differences were found in all years concerning the herbaceous layer. As for the average importance value, Euonymus oxyphyllus (18.23%), Acer pseudosieboldianum (16.48%), and Callicarpa japonica (13.85%) were dominant in the shrub layer, while Ainsliaea acerifolia (23.41%), Disporum smilacinum (9.45%), and Oplismenus undulatifolius (5.62%) were dominant in the herbaceous layer. In the shrub layer, the richness of Smilax china, Lonicera subsessilis, and Philadelphus schrenkii was high when the basal area and the stand density of an upper layer were high. By contrast, smaller basal area and stand density were associated with the richness of Acer pseudosieboldianum, Deutzia glabrata, Morus bombycis, and Cornus kousa. Furthermore, it was found out that the impact of the basal area and the stand density on the herbaceous layer decreased over time, while the herb layer's species composition was greatly affected by cover degrees of Euonymus oxyphyllus and Acer pseudosieboldianum in the shrub layer. In conclusion, the number of species in the understory vegetation in Gwangneung forest is continuously decreasing, thus implying that species diversity, basal area, and stand density of an upper layer can influence the species composition in understory vegetation.