• Journal of Korean Society of Forest Science
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• v.100 no.1
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• pp.95-104
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• 2011

Distribution types of native conifers (Juniperus chinensis, Pinus parviflora, Tusga sieboldii and Taxus cuspidata var. latifolia) were studied by phytosociological investigation and ZM method in Ulleung Island, South Korea. Two main types were divided maritime vegetation (Juniperus chinensis forest) and mountain vegetation (Taxus cuspidata var. latifolia forest and Pinus parviflora-Tusga sieboldii forest). The former was divided into sea cliff distribution (J-SC) and sea ridge distribution (J-SR) type. The latter was classified 7 distribution types; Taxus cuspidata var. latifolia forest was rock distribution (Ta-R) and mountain slope distribution (Ta-MS) type, and Pinus parviflora-Tusga sieboldii forest was rock distribution (P T-R), upper and ridge distribution (P T-UR, 3 units sub-types:1sub, 2sub, 3sub), and Mountain slope distribution (P T-MS) type. It was considered that J-SC, Ta- R, and P T-R were maintained by topographic climax, but J-SR, Ta-MS, P T-UR and P T-MS were the process of vegetation succession. Distribution types of topographic climax are entrusted to process of vegetation succession. Types in the process of vegetation succession will be needed tending of forest to promote saplings growth and seedlings germination. Especially in order to restore Tsuga sieboldii forest should be afforest and make forest gap because It is mid shade tolerant tree and purity percentage of its seed is 1~2%. It was considered that the composition of group mixture forest constituted Pinus parviflora, Tsuga sieboldii, Taxus cuspidata, Camellia japonica, Machilus thunbergii and Acer okamotoanum, etc. will be able to restore native vegetation, after take the form of forest gap by strong thinning and pruning of Pinus thunbergii forest.

• Korean Journal of Remote Sensing
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• v.39 no.6_1
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• pp.1341-1352
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• 2023

The normalized difference vegetation index (NDVI) derived from satellite images is a crucial tool to monitor forests and agriculture for broad areas because the periodic acquisition of the data is ensured. However, optical sensor-based vegetation indices(VI) are not accessible in some areas covered by clouds. This paper presented a synthetic aperture radar (SAR) based approach to retrieval of the optical sensor-based NDVI using machine learning. SAR system can observe the land surface day and night in all weather conditions. Radar vegetation indices (RVI) from the Sentinel-1 vertical-vertical (VV) and vertical-horizontal (VH) polarizations, surface elevation, and air temperature are used as the input features for an automated machine learning (AutoML) model to conduct the gap-filling of the Sentinel-2 NDVI. The mean bias error (MAE) was 7.214E-05, and the correlation coefficient (CC) was 0.878, demonstrating the feasibility of the proposed method. This approach can be applied to gap-free nationwide NDVI construction using Sentinel-1 and Sentinel-2 images for environmental monitoring and resource management.

• Korean Journal of Agricultural Science
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• v.30 no.1
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• pp.41-58
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• 2003

This study was conducted to investigate bird community and to suggest a proper way how to manage protect bird community in Gap stream. The survey was carried out over four sections by the line transect method and point counts method from September 2001 to August 2002. Natural stream region as Gasuwon Bridge - Mannyeon Bridge are observed birds were 11 orders 29 families 67 species, Artificial stream region as Mannyeon Bridge - Daedeok Bridge are observed birds were 6 orders 10 families 30 species, Daedeok Bridge - Wonchon Bridge are 8 orders 12 families 28 species, Wonchon Bridge - Gap Stream Bridge are 8 orders 18 families 40 species. All the observed birds in artificial stream region are 8 orders 19 families 47 species. Number of species in natural stream region was higher than artificial stream region owe to a various habitat environment such as forest, cultivated land, streamside forest, sandy plain, gravelly field, reedy field etc. and can not add with the interface and the usage of the human. Number of species in artificial stream region was lower than natural stream region owe to a simple habitat environment and the water ecosystem is severed with embankment block and grass plot with the land ecosystem. The furtherance of various habitat environment which considers the ecosystem like the natural stream as the water ecosystem is joined together with the land ecosystem is desired to attract various wildbirds in Gap stream. The design is desired with the maintenance of the stream to consider the stream corridor which plays ecological important role as connect the fragment habitats.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.1
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• pp.16-22
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• 2014

This study was conducted to determine the changes in soil chemical properties and the growth of seedling according to the different dredged soil improving methods at slope of Saemangeum sea dike. Undersea dredged soil was improved by five different methods. Seedlings of Ulmus davidiana var. japonica, Chionanthus retusa, Celtis sinensis, and Pinus thunbergii were planted after 9 month of experience site installation, then soil pH, NaCl concentration in soil, soil organic matter (SOM), and survival rate and height of seedling was measured. Initial soil pH was highest in the control plot but it decreased to the similar level with other soil improving plots after 35 months. There were no differences in NaCl concentration between the control and soil improving plots, and it showed decreasing tendency during the study period. In the control plot, initial SOM was lowest among that of other plots during the study period. The survival rate of 36 months after planting of P. thunbergii was highest among the species. The gap of the tree growth of P. thunbergii between the control plot and the soil improving plots was small, however, other species showed relatively higher tree height in the soil improving plots than the control plots. Creation forest with P. thunbergii might be a cost effective afforestation in coastal reclaimed land since it rarely needs additional improvement of dredged soil.

• Journal of Ecology and Environment
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• v.32 no.2
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• pp.87-96
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• 2009

Pinus thunbergii plantations in Pohang-si, Gyeongsangbuk-do, Korea, are of low ecological quality, with arrested succession and a high proportion of ruderal species. To improve the quality of the habitat, we created canopy gaps ($\sim42\;m^2$) and monitored changes in abiotic (light availability, canopy openness) and biotic (survival and growth of seedlings and understory communities) variables in 2007 and 2008 in plots that had received one of five types of treatment: cutting of canopy trees and removal of the understory (CU), cutting of canopy trees only (C), girdling of canopy trees and removal of the understory (GU), girdling of canopy trees (G) or control. Each treatment was applied to three replicate plots. Abiotic variables did not significantly differ among treatments. Survival rates of target species were slightly lower in the CU, G and control conditions. Based on logistic regression analysis, the only significant growth factor affecting survival was height growth. Positive effects of seedling height and leaf area growth on survival were also detected, but did not reach statistical significance. In treatment G, gradual improvement of overstory conditions and mitigation of competition by limitation of disturbance to the understory community were likely to have promoted seedling growth. There were no significant effects of gap treatments on changes in species abundance (cover and richness) and composition of understory between the study years. This result implies that the small gaps created in our study may be below the threshold size to affect understory growth. However, the results of this study are based on a short-term investigation of only two years. Long-term research is strongly recommended to clarify the effects of gap treatment on plant communities in afforested areas.

• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.447-455
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• 1995

Regeneration process of a mongolian oak forest in Bukam-Ryeong area, Mt. Jumbong, Kangwon-Do, was studied in relation to its structure. The dominant trees of the stands came up beyond 10m in height. The upper-tree layer was highly dominated by oaks, and they distributed horizontally in random. Oak trees of the middle layer and the lower layer were few in number and small in basal area, and tended to be distributed contagiously. In the trees of the upper layer, the distribution of the age tended to be two modal type which has the mode of 70 and 230 years in plot. In the horizontal distribution of these trees, some of the even-aged cluster which were constituted of several trees, were found. The rate of the stern diameter increment during first 25 years of the oaks in upper layer were higher than those of the same species in the middle layer. These results showed that after the forest canopy had been broken out, the seedlings which were established in dense there grow with the decreasing density and some of these, of which distribution became in random, would constitute the canopy.

• Fire Science and Engineering
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• v.29 no.1
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• pp.45-52
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• 2015

This research analyzed synthetically the characteristic of forest helicopter, fire helicopter, civil helicopter and deployment assets are in operated in forest fire places of our country. Looking at arrangement of helicopter, Chung-buk, Jeonnam has a number of outbreak a forest fire rather than others but it is weak of initial fire attack by a gap of helicopter arrangement. Geong-gi has many helicopter while it is a relatively few outbreak of a helicopter. According to this, We read to consider that Gang-won need to rent more a helicopters and civil helicopter in each weak areas by government expense. In addition Dae-jeon, Chung-buk and Jeon-nam need arrangement of helicopter after secure rental budget. Especially, Dae-jeon need to consider opening base of fire helicopter.

• Journal of Ecology and Environment
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• v.31 no.3
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• pp.167-176
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• 2008

Atmospheric N deposition has far-reaching impacts on forest ecosystems, including on-site impacts such as soil acidification, fertilization, and nutrient imbalances, and off-site environmental impacts such as nitrate leaching and nitrous oxide emission. Although chronic N deposition has been believed to lead to forest N saturation, recent evidence suggests that N retention capacity, particularly in the forest floor, can be surprisingly high even under high N deposition. This review aims to provide an overview of N retention processes in the forest floor and the implications of changing C-N interactions for C sequestration. The fate of available N in forest soils has been explained by the competitive balance between tree roots, soil heterotrophs, and nitrifiers. However, high rates of N retention have been observed in numerous N addition experiments without noticeable increases in tree growth and soil respiration. Alternative hypotheses have been proposed to explain the gap between the input and loss of N in N-enriched, C-limited systems, including abiotic immobilization and mycorrhizal assimilation, both of which do not require additional C sources to incorporate N in soil N pools. Different fates of N in the forest floor have different implications for C sequestration. N-induced tree growth can enhance C accumulation in tree biomass as observed across temperate regions. C loss from forests can amount to or outweigh C gain in N-saturated, declining forests, while another type of 'C-N decoupling' can have positive or neutral effects on soil C sequestration through hampered organic matter decomposition or abiotic N immobilization, respectively.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2006.10a
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• pp.171-174
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• 2006

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2005.10a
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• pp.141-144
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• 2005