• Journal of Forest and Environmental Science
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• v.36 no.2
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• pp.91-112
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• 2020

In Ethiopia, dry land vegetation including the fairly intact lowland and western escarpment woodlands occupy the largest vegetation resource of the country. These forests play a central role in environmental regulation and socio-economic assets, yet they received less scientific attention than the moist forests. This study evaluated the woody plant species composition, population structure and carbon sequestration potential of the A. senegal woodland across three distance gradients from the settlements. A total of 45 sample quadrants were laid along a systematically established nine parallel transect lines to collect vegetation and soil data across distance gradients from settlement. Mature tree dry biomass with DBH>2.5 cm was estimated using allometric equations. A total of 41 woody plant species that belong to 20 families were recorded and A. senegal was the dominant species with 56.4 IVI value. Woody plant species diversity, density and richness were significantly higher in the distant plots compared to the nearest plots to settlement (p<0.05). The cumulative DBH class distribution of all individuals had showed an interrupted inverted J-shape population pattern. There were 19 species without seedlings, 15 species without saplings and 14 species without both seedlings and saplings. A significant above ground carbon (5.3 to 12.7 ton ha^-1), root carbon (1.6 to 3.6 ton ha^-1), soil organic carbon (35.6 to 44.5 ton ha^-1), total carbon stock (42.5 to 60.7 ton ha^-1) and total carbon dioxide equivalent (157.7 to 222.8 ton ha^-1) was observed consistently with an increasing of distance from settlement (p<0.05). Distance from settlement had significant and positive correlation with species diversity and carbon stock at 0.64^⁎⁎ and 0.78^⁎⁎. Disturbance intensity may directly influence the variation of species composition, richness and density along the A. senegal woodland. The sustainability of the A. senegal woodland needs urgent protection, conservation and restoration.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.380-388
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• 2017

Factors affecting spatial distribution of halophytes were analyzed in June 2012 at the Goraebul coastal dunes. In the Goraebul sand dune, distribution of halophytes was divided into three groups. The first group belonging to Elymus mollis, Carex kobomugi, Calystegia soldanella, Ixeris repens and Glehnia littoralis was distributed in the ridge of primary sand dune and dune slack. The second group belonging to Lathyrus japonicus and Zoysia macrostachya was distributed in the dune slack. The third group belonging to Pinus thunbergii, Vitex rotundifolia and Linaria japonicus was distributed in the pine forest of the secondary sand dune. E. mollis, C. kobomugi, C. soldanella, I. repens and G. littoralis was distributed in relatively unstable habitat of sand dunes due to the large amount of sand movement. V. rotundifolia was distributed in a relatively stable habitat. Factors that have the greatest influence on distribution of halophytes in the Goraebul sand dunes are distance from the seashore, topography, and the pine forest. The Goraebul sand dune is a relatively well-preserved area with minimal human intervention. Therefore, different distribution of physico-chemical factors by natural processes is essential to spatial distribution of halophytes than other sand dunes in Korea. Significant natural processes in the Goraebul sand dunes were advance and retreat of coastlines from waves, erosion and sedimentation of sand due to wind and waves, and dispersal of seawater.

• The Korean Journal of Ecology
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• v.26 no.5
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• pp.223-236
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• 2003

The vegetation in this study area was divided into 10 plant communities: Pinus thunbergii, P. densiflora, Quercus acutissima, Q. mongolica, Q. serratea, Q. variabilis, Q. aliena, Q. dentata, Carpinus coreana, Betula davurica and 3 afforestations; Pinus rigida, Robinia pseudo-acacia, Castanea crenata. The dominant species in each stratum as determined by R-NCD appeared to be Q. acutissima, P. densiflora, Platycarya strobilacea, Sorbus alnifolia and Q. aliena in the tree-2 layer, Rhododendron mucronulatum, P. strobilacea, Q. serrata, Q. aliena and Q. acutissima in the shrub layer, and Carex lanceolata, C. humilis, R. mucronulatum, Mischanthus sinensis var. purpurascens and Oplismenus undulatifolius in the herb layer. The distribution of diameter at breast height(DBH) showed the highest percentage (56%) in the range of 2∼10㎝ in the study area and it was investigated as being in the restoration phase after disturbance. The average of the age of trees was under 40-years-od. The pH of soil collected at each site appeared to be within the range between 4.53 and 5.10(the average of 4.73) in each community, organic matters appeared higher than the value in Q. mongolica, P. rigida, C. crenata communities compared to P. thunbergii, P. densiflora communities. And soil organic matters and total nitrogen were highly correlated with their contents.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.5
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• pp.755-763
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• 2010

Fine sediment loadings from agricultural watersheds have led to habitat degradation in Lake Takkobu, northern Japan. Fifteen lake sediment core samples were obtained and analyzed to develop a chronology using physical sediment characters, $^{137}Cs$, and tephra. The reconstructed sedimentation rates over the past ca 300 years suggested that sedimentation rates increased drastically after land use development. With a natural sedimentation rate of 0.1-1.1 mm $year^{-1}$ until 1898, lake sedimentation accelerated to 0.6-12.8 mm $year^{-1}$ after 1898. The sedimentation rates after land use change, such as forestry, river engineering works, and agricultural development, were about 6-12 times higher than that under natural conditions, leading to accelerated lake shallowing over the last ca 100 years. Sedimentation rates between 1898 and 1963 differed with location in the lake because of spatial variation in the sediment flux from the contributing rivers and their watersheds. The sedimentation rate in the southern zone between 1898 and 1963 was significantly higher than that in the middle and northern zones, reflecting active sediment production associated with forestry for charcoal production and canal construction for transportation in the southern watersheds and wetlands. The sedimentation rate after 1963 did not vary among the three zones, because decreasing sedimentation was found in most of the southern sites whereas an increasing trend was observed in the middle and northern sites. This result can be explained by shallowing of lake-bottom morphology with sedimentation and the resultant reduction of sediment retention capacity in the southern zone. Moreover, the sedimentation rate at sampling sites close to river mouths increased by 5-32 times compared with natural rates before 1898. The Kushiro River, into which Lake Takkobu drains under regular flow conditions, further contributed to an increased sedimentation rate, because water from the Kushiro River flows back into Lake Takkobu during floods.

• Korean Journal of Environmental Biology
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• v.37 no.3
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• pp.229-248
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• 2019

This study was carried out to investigate the flora of Mt. Jaamsan on the Gyeongsang supergroup, Korea. From the results of eight field surveys from March to October 2017, we have identified 530 total taxa, representing 483 species, eight subspecies, 35 varieties, two forms, and two hybrids, which were placed in 325 genera and 110 families. The plant formation of Mt. Jaamsan is the deciduous broad-leaved and conifer mixed forests, which are the common ones in the middle part of the Korean Peninsula. Most of the mountain is covered with young secondary forest, which is mainly composed of Quercus spp., and Pinus. Out of these 530 taxa, 12 are endemic to Korea, 17 taxa are listed on the Korean Red List of threatened species, 65 are floristic target species, and 55 are invasive alien species. The percentage of naturalized index(NI) and urbanization index (UI) were 10.4% and 17.2%, respectively. Mt. Jaamsan has a high plant diversity, including endemic and rare species, which consist of geomorphological landscapes. We considered that the composition and distribution of species are affected by the different environmental factors according to the sedimentary rocks, drying ridges, valleys, and streams. Together with the rocks and soils were the substrate type that play a major role in providing the unique habitats for sun plants in the area.

• Journal of Korean Society of Forest Science
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• v.28 no.1
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• pp.67-96
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• 1975

The serious consequences of the roadside erosion and its impact on sedimentation and deterioration of roadside landscape continue to be documented in Koreas. An analysis on the landscape conservation treatments was made through the field survey for the 8 radial roadsides around Seoul area. This was performed to identify and evaluate the present restoration measures, and to establish the practical standard measures for the landscape conservation treatments on the cut-and banking roadside slopes.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.369-378
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• 1991

Major statutory nature protection areas include Nature Parks, Nature Reserves. Nature Ecological System Protected Areas. Biosphere Reserves, Nature Protected Forests, Wildlife Sanctuaries, and Protection Forests with total area of 1,124,000 ha. These protected areas cover almost 18% of the forested area. The number of visitors of NPs reached over 33 million per year with sharp increasing rate over the years. To protect the deteriorated hiking trails and camp grounds caused by overuse, two management policies have been implemented : cooking prohibition and natural rest rotation system. While prohibition of cooking is based on the fact that most of the solid wastes in nature parks are leftovers of cooking, natural rest rotation system is mainly for rehabilitation of deteriorated areas by natural processes. The system has closed 47 trails(in 27 mountains) throughout the country since January 1991, which is scheduled to continue 3 years. Due to the lack of accumulated scientific knowledge on how, when and where to close, application of the system leaves much to be desired. This paper discusses the current efforts to protect the natural resources for recreational use and suggests future directions for an effective policy implementation.

• Korean Journal of Environment and Ecology
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• v.25 no.5
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• pp.710-716
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• 2011

The growth characteristics and the several component content of leaves in one year old tetraploid of Robinia pseudoacacia introduced at five site planted respectively were surveyed in Sangwon area Pyongyang, and the expand plant possibility and the leaves harvested as feed additive use of possibility in Democratic People's Republic of Korea was discussed in comparison with tetraploid of R. pseudoacacia of Yanqing area. The results were as follows (1) the length and stump diameter of annual sprouting stems at Sangwon area were smaller 50% than the tetraploiod of R. pseudoacacia stems that Yanqing area; (2) the length of sprouting stems in slope sites of Eastern (E), Western(W) and Southern(S) at Sangwon were higher 23~30% than the length that Northern slope site(N), and the diameters of sprouting stem in the slope of Eastern(E) and Southern(S) were higher 14~23% than the slope sites of Northern(N) and Western(W); (3) crude protein contents and ash contents of leaves at Sangwon were higher 40% general R. pseudoacacia and similar to the leaves that Yanqing area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.21 no.3
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• pp.103-111
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• 2016

Seasonal dynamics of kelp forest-forming algae, Ecklonia cava population formed following the large-scale disturbance by Typhoon 'Bolaven' in August 2012 were investigated in Jeju Island, Korea. Morphological characteristics, recruits density, mortality rate, total density and biomass were monitored bimonthly from June 2013 to June 2015. Total and longest blade lengths, and individual weight of E. cava showed distinct seasonal trends. Stipe length increased from winter to spring, but did not show increase or reduced from summer to autumn. This indicates that morphological characteristics of E. cava are mainly affected by the change of blades. The optimal temperature for E. cava growth was about $15-18^{\circ}C$ during winter to spring while the growths were inhibited at the water temperature above $20^{\circ}C$ during summer. E. cava exhibited very low recruitment during spring-summer. However, high recruitment was observed on April 2015 when canopy cover was very low due to low density. This indicates that recruitment of E. cava was controlled not by seasonal effects but by physical factors such as canopy and space. The mortality rate of juvenile plants was highest due to their unstable settlement. By June 2015, 34 months after the disturbances, E. cava was almost recovered to the pre-disturbance population size structure. These results suggest that recovery of kelp forest following the large-scale disturbance requires a considerable period of time (more than three years). This study should provide valuable ecological information on management, restoration and protection of kelp species.

• FLOWER RESEARCH JOURNAL
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• v.18 no.1
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• pp.29-32
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• 2010

This study was conducted to determine the effects of cutting position, media, and auxin on rooting of Artemisia keiskeana cuttings. In the cutting positions, the cutting of middle and basal positions had a better growth in the both upper and lower part than the cutting of the top position. Especially, the cutting of the middle position showed the highest rooting rate, at 68.3%. In the media, peatmoss showed the latest date on the rooting initiation. Also, the growth, survival rate and rooting rate of the upper part and lower part were low. However, the cutting in vermiculate showed the fastest date on the rooting initiation, and had a significant effect on the growth of the upper part and lower part, showing the highest rooting rate and survival rate in all tested media. When cuttings were treated by auxin, the rooting rate and growth of cuttings were higher than the control. The control showed the lowest rooting rate, at 41%, while, the auxin treatment showed the highest, rate over 80%. Whereas when treated by NAA, the lower part of cuttings had a better growth than these treated by IBA. Also, the higher the concentration of auxin was, the higher the rooting rate and growth rate of Artemisia keiskeana cuttings were.