• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.240-245
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• 2011

Vegetation changes were studied for 16 yr in clearcut logged Pinus densiflora forests in the southern Gangwon-do province in Korea by applying chronosequence approach. Ambient temperature and relative humidity, Detrended Correspondence Analysis (DCA), Multiple Responses Permutation Procedure (MRPP), Indicator Species Analysis (ISPAN) were used to examine successional trajectory and compositional changes. After clearcutting, canopy openness was increased abruptly at three folds (1yr 68.3% and R1 23.0%) and then decreased, but relative moisture was slightly decreased (6%) compare to control site. In the result of DCA, right after clear cutting, vegetation composition was developed heterogeneously compared to control sites, and then approached to control sites within 16 years. Based on MRPP, species composition of each developmental stages (1yr, 3yr, 10yr and 16yr) revealed signigicant differences to that of control vegetation (R1, R3, R10 and R16). Indicator species in 1yr and 3yr samples included various woody species rather than herbaceous species, but in 10yr and 16yr, herbaceous were more abundant. Earlier succession of pine forests likely can explain to Initial Floristic Composition (IFC) Model.

• Korean Journal of Environment and Ecology
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• v.19 no.3
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• pp.258-268
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• 2005

The objective of this study was to monitor the edge vegetation development process after timber harvesting at deciduous hardwood forest in Seoul National University Research Forest of Baekwoonsan (Mt), Korea The results from the 4th (2001) and 5th (2003) survey for edge vegetation development process after timber harvesting are summarized as follows. The competitive species at the harvested forest edge are Lindera erythrocarpa, Weigela subsessilis, Lespedeza maximowiczii, Lindera obtusiioba, Arajia eiata. There were Lindera erythrocarpa, Ivelgela subsessilis, Staphyiea bumaida as competitive species at harvested forest border between harvested forest edge and harvested interior. And at the forest interior, the competitive species were Lindera erythrocarpa, Lindera obtusiloba. There were differences in the competitive species at the forest edge due to the differences in direction, altitude, and existing dominant species. But Lindera erythrocarpa, Weigela subsessilis were appeared to be a competitive specieg at the southwestern slope (A site) and northeastern slope (B site). After timber harvesting, Sasa borealisshowed a good growth in early days, but showed a tendency of declining with the developing of canopy layer And coverage was generally higher at the Northeastern slope (Site B) than southwestern slop (Site A). The similarity index was lower as the distance from the forest edge becomes farther.

• Journal of Korean Society of Forest Science
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• v.90 no.3
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• pp.242-248
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• 2001

Changes in land-use can affect soil organic matter content and fertility. We compared total soil carbon and nitrogen concentrations, soil respiration, and nitrogen availability under three land-use types in central Korea; conversion of old rice field to natural willow-maple (Salix-Acer) forest, conversion of old field to artificial Korean pine (Pines koraiensis) forest, and indigenous oak (Quercus spp.) forest. After 20 years of fallow the area of rice field conversion to forest had higher soil carbon and nitrogen concentrations in the soil depth of 0-10cm and 10-20cm than the areas of field conversion to Korean pine forest and indigenous forest. In general, soil carbon and nitrogen concentrations decreased with soil depth. Organic matter accumulation as a balance of input and decomposition seemed to be higher in the soil of previous rice field, and carbon and nitrogen accumulation was largely confined to the topsoil. Soil respiration rates were greatest at the area of rice field conversion to forest, and appeared to be related to soil carbon and soil moisture. Soil nitrogen availability measured by the ion exchange resin bag method differed significantly among land-use types; soil inorganic nitrogen ($NH_4{^+}+NO_3{^-}$) and ammonium availability were highest in the soil under indigenous oak forest followed by conversion of old field to artificial Korean pine forest and conversion of old field to natural willow-maple forest.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.336-343
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• 2018

This study was carried out to provide the technology of silvicultural practices and management for regeneration by sprouts in the oak forests distributed on the slope. A total of 1,451 stumps were examined for the following factors relative to the occurrence and growth of the sprouts: stump height & diameter; location & quantity and root collar diameter & height of arisen sprouts. The amount of sprouts deceased or increased as the stump diameter increased. However, it tended to increase with stump height. The difference in the stump height between direction of the upwards (DUS) and downward slopes (DDS) was occurred, because oak trees were felled lower based on direction of the upward for convenience of regeneration works on the slope. The number of sprouts was higher relatively in the stumps of DDS. The rate of arisen side and root sprouts was higher in the stumps of DDS and DUS, respectively. The stump height difference was found to affect the arisen part of sprouts. As a result of comparing the sprouts growth according to the arisen part, there was no difference in the stump of DUS, but the growth of side sprouts in the stump of DDS was higher than that of the root. In order to improve the quality of oak sprouts considering the distribution characteristics of the oak forests in South Korea, it is necessary to apply the silvicultural technique, making the cutting surface parallel with the slope to reduce the stump height difference, to suppress arising side sprouts.

• Economic and Environmental Geology
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• v.54 no.4
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• pp.457-464
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• 2021

The objectives of this study were to analyze of soil chemical characteristics of abandoned coal mine forest rehabilitation areas in Gangwon-do. The study sites were 8 areas and the investigations were performed 11 times according to elapsed time. Soil characteristics were soil pH, TOC, Total-N, C/N ratio, and Av. P₂O₅. Soil pH and Av. P₂O₅ were decreased according to elapsed time after forest rehabilitation, while TOC, Total-N, and C/N ratio increased. TOC and Total-N arrived at quality requirements of covering soil for forest rehabilitation in abandoned coal mine area passed 10 years after forest rehabilitation, while soil pH became lower than that. Therefore, it needs long-term monitoring of soil chemical characteristics after the forest rehabilitation and to establish post management.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.480-487
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• 2000

Repeated measurement of 472 permanent subplots in slash pine (Pinus elliottii Engelm.) plantations were used to develop survival prediction equations for predicting future number of planted slash pine trees. On the average, about 40 percent of the slash pines in the experimental sites had a stem cankers due to fusiform rust (Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp. fusiforme) incidence. A stand level survival prediction model was developed that incorporated the incidence of fusiform rust and allowed the transition paths of trees from an uninfected stage to an infected stage. Predicted total surviving number of trees is obtained by adding together the predicted number of infected and uninfected trees. The influence of natural hardwood density and site quality on slash pine survivals tended to show a negative effects on future survivals.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.2
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• pp.42-54
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• 2023

The population is concentrated in the metropolitan areas in Korea, and low-density residential areas are transforming into high density residential areas through redevelopment to meet this demand. However, large-scale redevelopment in a short period of time has a negative impact on the urban climate, such as generating a heat island effect due to the reduction of urban green areas. In this study, the change in surface temperature from 2013 to 2022 in the redevelpment areas of Godeok-dong and Dunchon-dong, Gangdong-gu, Seoul, was analyzed using Landsat 8 satellite images. In the Godeok-dong area, the difference in surface temperature was analyzed for the target redevelopment area, forest area, mixed forest and urban area, and low density residential area. In the Dunchon-dong area, the difference in surface temperature was analyzed for the target redevelopment area, forest area, and low density residential area. The difference in surface temperature was analyzed through multiple regression analysis conducted yearly over the three different stages in redevelopment period. The results from the multiple regression analysis show that in both areas, the land surface temperature of target redevelopment area was higher than that of the forest area and lower than low density residential area. It can be seen that these results occurred because the low-density residential area in Godeok-dong and Dunchon-dong had a lower green area ratio and a higher building-to-land ratio than the target redevelopment area. The results of this study suggest that even if low-density residential areas are transforming into high-density areas, adjusting the management of green areas and building-to-land ratio can contribute to lessen urban heat island effect.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.189-196
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• 2020

Mosquitos serve as vectors for diseases, causing inconvenience as well as a threat to human life and health. Concern about mosquitos introducing and spreading new diseases has been intensifying. We observed a variety of mosquito habitats based on land cover classification from Korea's Ministry of Environment, and the mosquito species that could appear were classified according to the each habitat type. Finally, we suggested the best control methods for each type of habitat considering habitat characteristics and the ecological traits of mosquitos. Urban areas harbor various habitats for pests, contributing significantly to mosquito habitats. Control must be performed regarding larva and adults because various sources for habitats exist. Public mosquito control programs such as educational training, as well as information brochures can be effective in managing mosquito populations and public health. Agricultural areas show high densities of mosquito larva to lentic zones such as reservoirs, wetlands, paddy fields. So, biological control using natural predators may be effective in controlling mosquito populations. Forests are major habitats for Aedes albopctus, so physical controls should be deployed for residents living nearby, and excessive deforestation should be minimized. Other areas including aquatic ecosystems should be adopted regarding biological control using Bti (Bacillus thuringiensis var. israelensis) and chemical control for eradicating mosquitos. We classified habitats into four types of land cover patterns considering ecological traits and habitat preference, and suggest adequate control methods for each habitat type. Our suggestion can be used to positively contribute toward effective managing mosquito's density and reducing the damage to public health.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.453-461
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• 2005

Structural characteristics and successional trends of actual forest vegetation in Youngil soil erosion control district, South Korea, were studied and described by the phytosociological investigations and diameter measurement. And also the incremental growth pattern of the major trees for erosion control analyzed using increment core. Sixty-eight releves were sampled with $100m^2$ plots. Two main vegetation types (Lespedeza bicolor-Miscanthus sinensis-type and Alnus firma-Styrax japonica-type) have been distinguished and typified nine vegetation units. Constancy classes diagram showed that the higher species (${\geq}IV$) have only 2.6% and that most species occurred were rare and had low abundances. The successional trends of the actual forest vegetation would be mostly changed as Quercus serrata forest. Annual diameter growth was 3.0~3.4 mm in case of conifer (Pinus rigida and Pinus thunbergii), and the broad-leaved trees (Alnus firma, Robinia pseudo-acacia, and Alnus hirsuta) showed 4.3~4.9 mm. The incremental growth patterns showed to be decreased rapidly since twenty to twenty-five years regardless of the species of trees.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1934-1938
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• 2008

In this study, the landuse pattern at the Gab river is analyzed using time-series aerial images. This study area is divided by two zones like as inland and floodplain. To begin with, in inland, the landuse area of items such as residential, road, industrial, public facilities is increased by following the urbanization. On the other hand, the area of the other items such as agricultural, forest and river is decreased. Also, the inclination of those two groups is reversed around 1988. Form the results, it is clarified that the Gab river is urbanized around 1988. In floodplain, the area of river is decreased as time goes by. This result means that the area of landuse factors such as level-upped riverside land, bridge, head work is increased conversely. Also, the proportion of the water to the river considering the hydrologic factor like rainfall is increased as time goes by. Overall, it is concluded that aerial image can be applied to get a landuse information that is needed in river management and planning.