• Journal of Wetlands Research
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• v.16 no.2
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• pp.213-220
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• 2014

Recently, river maintenance is change due to concern for the environment increases. Thus, the river restoration and river environment is best part of river maintenance. In case of Korea, existing river is improvement straightly for flood control and transportation. When the stream channel is straightly, maintain stability is important. Thus, construction of levees along the river. The various river structures for the purpose of flood control and transportation are inhibit factors of longitudinal and lateral connectivity. Connectivity is defined as the maintenance of lateral, longitudinal, and vertical pathways for biological, hydrological, and physical processes. Long-term point of view, increased connectivity is very important for a healthy ecosystem composition. As the first step of river restoration, this study described theory and concept of river continuum and the numerical model was applied to a real topography to simulate the flow analysis with or without segregated and blocked space in the Mankyung river. The results of this study can be utilized to develop the watershed connectivity assessments methods in order to the river restoration.

• Land and Housing Review
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• v.10 no.3
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• pp.43-55
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• 2019

The purpose of this study is to derive indicators and development directions to be considered when planning new towns in the Seoul metropolitan area as new towns are planned to be built. To this end, the following implications were derived after analyzing the survey data of experts in each field using Frequency Analysis and Analysis of Variance(ANOVA) technique. First, the assessment results of the existing first and second phase new towns showed that there were many negative assessments of citizen participation and information sharing, smart technologies and services, social and cultural diversity and inclusion. Regarding the third phase new town, experts said that the most important indicators are accessibility and convenience of transportation, environmental comfort, quality and service of residence. In addition, experts cited the superiority of landscape/design, jobs/self-sufficiency and social/cultural diversity as important indicators. Second, after examining whether the perceptions and assessments of experts differ depending on individual characteristics such as gender, age, occupation, and professional field, the first and second phase new towns showed significant differences only in "gender", and the third phase new town had significant differences in "gender" and "professional field". Third, experts thought that changes in population structure, industry and jobs, quality of life and diversity, environment and climate change, and social and residential welfare should be considered important in the planning of third phase new town. In addition, experts considered expanding park and self-sufficient land as important in the land use plan, and ranked eco-city as a desirable type of the city, and public transportation facilities, park areas and education facilities as the most important living infrastructure.

• Journal of Korean Society of Forest Science
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• v.85 no.4
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• pp.656-666
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• 1996

Aspen demand has increased recently in the Great Lakes region in the United States. Since aspen has moved into the region in late 1800's, its growing stock has increased so as to change forestry industry of the Lake States. Intensive timber harvesting and biomass removal may cause nutrient depletion, especially on nutrient-poor sites. Forest nutrients and nutrient cycling were investigated in aspen stands of 7-10, 27-33, and 41-42 year-old growing on sandy soils in Minnesota. Nutrients added to the aspen stands by atmospheric deposition and soil weathering were efficiently absorbed and stored in the tree biomass. Aboveground biomass increased from $24.4t{\cdot}ha^{-1}$ at young stands to $139.2t{\cdot}ha^{-1}$ at mature stands. Nutrients accumulated in the tree biomass showed same magnitude of difference. Nutrients added to the site through atmospheric deposition were in the order of Ca, N, K, Mg, and P. Annual litterfall was greater in older stands. However, the amount of nutrients returned by litterfall was not significantly different among stand ages due to the greater nutrient contents in the litterfall of young stands. Litter decomposition and nutrient release rates were greater at young stands than at older stands. Likewise, nutrient availability was higher in young aspen stands and became lower as the stands grew older. Nutrient leaching loss was minimal at all stand ages. Soil N mineralization was greater at young stands than at older stands. Nutrient cycling process was facilitated in young aspen stands with an increased level of available nutrients, Based on the estimations of nutrient balance and nutrient removal by harvesting, Ca was the most critical element which was likely to be depleted if aspen stands are intensively harvested with short rotations.

• Korean Journal of Environment and Ecology
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• v.29 no.6
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• pp.907-916
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• 2015

The purpose of this study was to identify characteristics of vegetation structure, vegetation succession, and species diversity of artificially planted Chamaecyparis obtusa (CO) stands. The study was carried out by performing vegetation survey for eight CO stands located in Jeollanam-do Province, Korea. Analysis on vegetation classification and ordinations of the stands was conducted using the data from the vegetation survey, and as a result, the stands were classified into five types of communities. Community I showed a considerably lower index of species diversity when compared to other communities because the canopy of the dominant CO was so highly dense that the low-height vegetation was not able to develop or the low-height vegetation almost disappeared due to elimination of weed trees. Meanwhile, the Community II - IV had relatively higher indices of species diversity because various native tree species mixed with the low-height vegetation and competed with each other in the understory and shrub layers to some degree of stability or in their early stage of vegetation development. Community V, lastly, showed higher use intensity as a recreational forest, thus developing simpler vegetation structure on account of artificial intervention. There was positive correlation between photosynthetically active radiation entering the forest floor, number of observed species and index of species diversity. Such characteristics of vegetation structure in CO stands are closely associated with forest management and prescription for planting reforestation, thinning, and brush cutting in the past. There was a slight difference in vegetation structure and species diversity by communities, based on rotation time of the vegetational succession, process of disturbance frequency and disturbance, development, and maturity by planting CO stands. However, when compared to natural forests, the CO stands showed simpler vegetation structure. Because artificial forests are vulnerable in ecosystem service with lower species diversity, a drive for ecological management is needed for such forests to change into healthy ecosystems that can display functions of public benefit.

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.1-22
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• 2018

The purpose of this study is to provide the baseline data for conservation and management of Korean forest ecosystem by surveying and analyzing the vascular plants distributed from Gitdaebaegibong to Cheonghwasan in Baekdudaegan Mountains. The results are as follows. The numbers of vascular plants in the whole survey section were summarized as 771 taxa including 103 families, 379 genera, 623 species, 4 subspecies, 121 varieties and 23 forms. There were 377 taxa in A-section, 395 taxa in B-section, 278 taxa in C-section, 325 taxa in D-section, 534 taxa in E-section, and 406 taxa in F-section. The rare plants were 32 taxa including Megaleranthis saniculifolia, Rodgersia podophylla, Iris ensata var. spontanea, and Gastrodia elata. In IUCN Red List categories, there were 1 taxon of CR, EN, and DD each, 11 taxa of the VU, and 18 taxa of the LC. The Korean endemic plants were 26 taxa including Asarum versicolor, Clematis fusca var. coreana, Vicia chosenensis, Stewartia pseudocamellia, Carex okamotoi, and Luzula sudetica var. nipponica. The specific plants by floristic region were 143 taxa including 3 taxa of grade V, 12 taxa of grade IV, 41 taxa of grade III, 42 taxa of grade II, and 45 taxa of grade I. The naturalized plants were 41 taxa including Rumex crispus, Ailanthus altissima, Erechtites hieracifolia, Erigeron annuus, and Poa pratensis. The invasive alien plants were 4 taxa including Rumex acetocella, Sicyos angulatus, Ambrosia artemisiifolia, and Aster pilosus. The plants adaptable to climate change were 43 taxa including 14 taxa of endemic plants, 2 taxa of southern plants, and 27 taxa of northern plants.

• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.448-463
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• 2006

This study analyzed the changes in vegetation structure of Quercus mongolica communities, Pinus densiflora communities, Robinia pseudo-acacia communities and Pinus rigida communities for the last 11 years$(1994{\sim}2005)$ to provide basic data for ecological restoration. We studied the vegetation structure of four communities within a plot$(unit:\;1,200m^2)$) and concluded that Canopy Layer continuously preserved and expanded existing superior species, Understory Layer grew Styrax japonica which is highly adaptive to urban environment, and Shrub Layer grew more Stephanandra incise. An analysis on species diversity indicated that Quercus mongolica communities$(1.0921{\rightarrow}1.0381{\rightarrow}1.0633)$, Pin us densiflora communities$(0.7071{\rightarrow}0.8553{\rightarrow}1.0164)$, and Robinia pseudo-acacia communities$(0.9255{\rightarrow}0.8392{\rightarrow}0.8721)$ sharply decreased in 1998 and are gradually increasing these days. Also, Pinus rigida communities decreased from 0.9008 in 1998 to 0.8850 in 2005. Fluctuation in numbers of species and trees were similar. Acidity of soil was $4.34{\sim}5.31$ and improved compared to 20 years ago.

• Korean Journal of Environment and Ecology
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• v.23 no.3
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• pp.258-271
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• 2009

Various environmental parameters change and ecological succession often lead to decline of Pinus densiflora forest in Seoul. Due to decline of it, we proposed the ecological management for conserving and improving from decrease of its dominant area on there. We analysed the P. densiflora forest's classification and suggested its ecological management that based on relation to competition between dominant species in the upper tree layer, the presence of competitive species in shrub layer and vegetation management standard. The Pinus densiflora forest types has been classified 6 types by ecological characteristics. The results from categorized its types are following as; 1) Pinus densiflora pure forest type; edaphic climax Pinus densiflora forest(26.1%), Pinus densiflora pure forest(21.5%). 2) the forest of Pinus densiflora and other species that compete with each other type; Pinus densiflora-Quercus mongolica forest(28.0%), Pinus densiflora-Pinus rigida forest(13.1%), Pinus densiflora-Quercus acutissima(4.2%). We conclude that the results in these kind of 4 types; Pinus densiflora pure forest type where possible to maintain the forest by edaphic climax, human trampling damage, vegetation management(e.x. remove the competition species, shrub layers management etc.) are mainly need to negative management. Whereas, the others 4 types; Pinus densiflora and other species(Quercus variabilis, foreign species, naturalized species etc.) that compete with each other types are need to positive management such as manage the same niche competition species, shrub layers management, remove the foreign species, naturalized species etc.. In these kinds of ecological management are very necessary to maintain Pinus densiflora forest.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.174-187
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• 2017

For the purpose of evaluating the restoration effect of vegetation, in this study, the areas where vegetation was restored had been monitored for 6 years, from 2008 to 2013. The areas were restored through some techniques by utilizing forest resources and nearby forest resources: biotope restoration method, forest topsoil paving method and small diameter trees planting method. Biotope restoration method is indicated the most similar properties to the existing natural forest just after they were restored because the forest likely to be deteriorated was transplanted. Forest topsoil paving method is expected that long-time will be taken for plants to grow to form the tree layer. However, the method is expected to acquire high restore the places of empty lands such as cutting areas. Community planting method is coverage can be increased for short time, relying on the sizes of planted trees, and the tree layer can be formed. Consequently, this method is expected to create high effect if the sizes of trees are considered after the right judgement of candidate site for restoration. This study is meaningful in that each type of restoration is monitored to observe the change of triggered by the succession process to forest. The study results can play as the reference data which can be utilized and applied to the area requiring vegetation restoration or to the area facing the damage of forest resources.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.573-580
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• 2006

A sediment core from the Cheollipo arboretum ($36^{\circ}$ 47' 57'N, $126^{\circ}$ 09' 04') was studied for pollen analysis in order to reconstruct postglacial vegetational change and environmental changes around the central western region of the Korean Peninsula. The record shows four pollen assemblage zones: Zone CHL-I, Quercus stage (ca. 9,300$\sim$6,200 yr BP): zone CHL-II, Quercus-Pinus stage (ca. 6,200$\sim$4,600 yr BP); zone CHL- III, Pinus-Quercus stage (ca. 4,600$\sim$1,160 yr BP): zone CHL-IV and Pinus stage (ca. 1,160 yr BP-present). During the 9,300$\sim$8,500 yr BP, the early Holocene, researchers have guessed a piece of cool-temperate norihern/altimontane mixed coniferous and deciduous broad-leaved forest. Between 8,500$\sim$4,600 yr BP the Quercus dominated the landscape of study area and the established dates of this typical cool-temperate central/montane deciduous broad-leaved forest vegetation might be ca. 6500 yr BP, and then the Pinus developed around the site at ca. 5,700 yr BP. The abrupt increase of Pinus and NAP (non-arboreal pollen) after ca. 1,100 yr BP indicates the vegetation changes due to human activities. From the dynamics of the Chenopodiaceae pollen indicating salt marsh and freshwater pollen flora such as Typha, Trapa, Nymphoides and so forth, we suggest that the tidal flat was altered into freshwater lake around 6,500 yr BP.

• Journal of the Korean Geographical Society
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• v.41 no.1 s.112
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• pp.73-93
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• 2006

Despite of ecological and landscape importances and public popularity of Pinaceae, not much scientific informations are known about Korean Pinaceae. Present work aims to understand the biogeography of Korean native Pinaceae, i.e., taxonomy, phylogeny, origin, life form, distribution, dispersal and migration. Korean native Pinaceae consists of five genera and sixteen species. Pinus is systematically closely related to Picea and Larix, but Abies is related to Tsuga. Boreal conifers which have migrated from NE Asia during the Pleistocene glacial epochs successfully survived, but now confined to the alpine and subalpine belts of the Korean Peninsula mainly due to climate warming since the Holocene. Species, such as Picea pungsanensis and Abies koreana have gradually adapted to local environment, and later became an endemic species of Korea. Disjunctive distribution of Pinus parviflora and Tsuga sieboldii are also indicatives of climate change of the Pleistocene. Major dispersal agent of pine trees with winged seed is wind, but wingless pine tree seeds seem to dispersed by birds and rodents. Pine trees with bigger wings are easily dispersed by wind, and now show broader distribution. Species of Pinaceae with disjunctive distribution on the alpine and subalpine belts of both North and South Korea seems to be more vulnerable to global warming.