• Title/Summary/Keyword: soil variables

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A Study on Forest Land Classification Using Multivariate Statistical Methods : A Case Study at Mt. Kwanak (다변수통계방법을 이용한 산지분류에 관한 연구)

  • 정순오
    • Journal of the Korean Institute of Landscape Architecture
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    • v.13 no.1
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    • pp.43-66
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    • 1985
  • Korea needs proper and rational public policies on conservation and use of forest land and other natural resources because of the accelerating expansion of national land developments in recent years. Unfortunately, there is no systematic planning system to support the needs. Generally, forest land use planning needs suitability analysis based on efficient land classification system. The goal of this study was to classify a forest land using multivariate satistical methods. A case study was carried out in winter of 1983 on a mountainous area higher than 100m above sea level located at Mt. Kwanak in Anyang -city, Kyung-gi-do (province). The study area was 19.80 km$^2$wide and was divided into 1, 383 Operational Taxonomic Units (OTU's) by a 120m$\times$120m grid. Fourteen descriptors were identified and quantified for each OTU from existing national land data : elevation, slope, aspect, terrain form, geologic material, surface soil permeability, topsoil type, depth of the solum, soil acidity, forest cover type, stand size class, stand age class, stand density class, and simple forest soil capability class. For this study, a FORTRAN IV program was written for input and output map data, and the computer statistics packages, SPSS and BMD, were used to perform the multivariate statistical analysis. Fourteen variables were analyzed to investigate the characteristics of their fire quench distribution and to estimate the correlation coefficients among them. Principal component analysis was executed to find the dimensions of forest land characteristics, and factor scores were used for proper samples of OTU throughout the study area. In order to develop the classes of forest land classification based on 102 surrogates, cluster and discriminant analyses of principal descriptor variable matrix were undertaken. Results obtained through a series of multivariate statistical analyses were as follows ; 1) Principal component analysis was proved to be a useful tool for data selection and identification of principal descriptor variables which represented the characteristics of forest land and facilitated the selection of samples.

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Physico-Chemical Properties on the Management Groups of Paddy Soils in Korea (우리나라 논토양(土壤) 유형별(類型別) 이화학적(理化學的) 특성(特性))

  • Hur, Bong-Koo;Rim, Sang-Kyu;Kim, Yoo-Hak;Lee, Ke-Yup
    • Korean Journal of Soil Science and Fertilizer
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    • v.30 no.1
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    • pp.62-66
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    • 1997
  • This study was designed to obtain the mean values of thirteen soil physico-chemical properties for different paddy soil management groups, and to serve the basic information for improving the soil using amendments. Computerized data on the results of detailed soil survey were used in this study. The clay contents in the B horizon of paddy soil management groups were 28.3% in the well adapted type, 11.8% in the sandy textured type, and 26.8% in the newly reclaimed type. Soil pH of B horizon in the paddy soil management groups except poorly drained type and acid sulfate type were higher than those of A horizon. In the river side paddy soils of well adapted type, the clay contents of A and B horizons were 16.8%, 23.1%, respectively, and soil organic matter contents of those horizons were 42g/kg, 18g/kg, respectively. And also available phosphate content of well adapted type was higher than the other types. Frequency of distribution of soil organic matter content levels in the B horizons of sandy textured type and newly reclaimed type were higher in the organic matter content range of below 10g/kg. And those of well adapted, poorly drained, and saline type were higher in the organic matter content range of 10~20g/kg. Correlation coefficients between 13 variables in the B horizon of well adapted type were all highly significant at 1% or 5% level, respectively.

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Development of Habitat Suitability Index for Habitat Restoration of Class I Endangered Wildlife, Cypripedium guttatum Cw. (멸종위기 야생생물 I 급 털복주머니란 서식지 복원을 위한 서식지 적합성 지수(HSI) 개발)

  • Yoon, Young-Jun;Kim, Sun-Ryoung;Jang, Rae-Ha;Han, Seung-Hyun;Lee, Dong-Jin;Shim, Yun-Jin;Park, Yong-Su
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.4
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    • pp.1-11
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    • 2020
  • This study aimed to develop the HSI (Habitat Suitability Index) model of Cypripedium guttatum. and to verify this model by applying to the candidate sites for replacement habitat. The development of HSI and SI (Suitability Index) model was conducted based on the existing literature, field surveys, and expert opinions for information on ecological habitat characteristics. Seven variables were selected as habitat variables including mean maximum temperature in Jul.-Aug., lighting, slope, altitude, effective soil depth, soil texture, and artificial overexploitation (i.e. protected areas). HSI model was developed for C. guttaum based on these variables. This HSI model showed high applicability to selection and evaluation of replacement habitats for C. guttaum. Our findings could provide the basic information on habitat assessment to prevent the extinction of endangered C. guttatum. However, since there is a limitation that the survey data were insufficient, further field surveys should be conducted on several habitat types to improve the accuracy of the HSI model.

A Study on the Community Structure of Vegetation Landscape in Naejangsan National Park(II) (내장산국립공원 식생경관의 군집모형에 관한 연구(II))

  • 이규완;심경구
    • Journal of the Korean Institute of Landscape Architecture
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    • v.22 no.1
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    • pp.85-100
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    • 1994
  • This study was to analyze the relationship between the community or species and environmental variables of the vegetation landscape in Naejangsan National Park. The analysis was performed by the ordination of DCA and CCA. The study was to compare and analyze the species composition status by the layer and the growth characterisics of the following vegetations ; Torreya nucifera community, Quercus variabilis - Acer palmatum community, Q. variabilis community, Q. variabilis - Sasa purpurascens community and Daphniphyllam macropodum community. The results are as follows; 1. The result of the study on the relationshkp between the stand scores of DCA ordination and environmental variables showed that the soil pH, the ammount of AV-P2O5 and the ammount of C.E.C. tend to increase while Pinus densiflora community changes to Q. variabilis - Q. serrata community and finally Carpinus laxiflora species community siginigicantly. The relation between the stand scores of CCA ordination and several enviromental variables suggested that the species of C. laxiflora and C. tschonoskii the species of Q. cariabilis and Q. serrata the species of C. pisifera, P. densiflora and Q. aliana in sequence grows in more fertile soil. 2. As the result of the analysis of the T. nucifera community showed, reproduction did not increase, and the characteristic of growth was not affected. The result is shown in the growth curve that was damaged by the climate and the human interference. 3. The A. palmatum was found to be as minor species in the middle layer and the crown areas did not have sufficient crown. 4. The result of the analysis of the relationship between Q. variabilis community and Q. variabilis - S. purpurascens community showed a decreasing tendency in the growth and number of species. 5. D. macropodum which constituted the dominance species in the middle layer had a nomal growth curve, and then the successional trend of D. macropodum species seems to be located in the climax species.

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Intercropping in Rubber Plantation Ontology for a Decision Support System

  • Phoksawat, Kornkanok;Mahmuddin, Massudi;Ta'a, Azman
    • Journal of Information Science Theory and Practice
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    • v.7 no.4
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    • pp.56-64
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    • 2019
  • Planting intercropping in rubber plantations is another alternative for generating more income for farmers. However, farmers still lack the knowledge of choosing plants. In addition, information for decision making comes from many sources and is knowledge accumulated by the expert. Therefore, this research aims to create a decision support system for growing rubber trees for individual farmers. It aims to get the highest income and the lowest cost by using semantic web technology so that farmers can access knowledge at all times and reduce the risk of growing crops, and also support the decision supporting system (DSS) to be more intelligent. The integrated intercropping ontology and rule are a part of the decision-making process for selecting plants that is suitable for individual rubber plots. A list of suitable plants is important for decision variables in the allocation of planting areas for each type of plant for multiple purposes. This article presents designing and developing the intercropping ontology for DSS which defines a class based on the principle of intercropping in rubber plantations. It is grouped according to the characteristics and condition of the area of the farmer as a concept of the rubber plantation. It consists of the age of rubber tree, spacing between rows of rubber trees, and water sources for use in agriculture and soil group, including slope, drainage, depth of soil, etc. The use of ontology for recommended plants suitable for individual farmers makes a contribution to the knowledge management field. Besides being useful in DSS by offering options with accuracy, it also reduces the complexity of the problem by reducing decision variables and condition variables in the multi-objective optimization model of DSS.

Modeling potential habitats for Pergularia tomentosa using maximum entropy model and effect of environmental variables on its quantitative characteristics in arid rangelands, southeastern Iran

  • Hosseini, Seyed Hamzeh;Azarnivand, Hossein;Ayyari, Mahdi;Chahooki, Mohammad Ali Zare;Erfanzadeh, Reza;Piacente, Sonia;Kheirandish, Reza
    • Journal of Ecology and Environment
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    • v.42 no.4
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    • pp.227-239
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    • 2018
  • Background: Predicting the potential habitat of plants in arid regions, especially for medicinal ones, is very important. Although Pergularia tomentosa is a key species for medicinal purposes, it appears in very low density in the arid rangelands of Iran, needing an urgent ecological attention. In this study, we modeled and predicted the potential habitat of P. tomentosa using maximum entropy, and the effects of environmental factors (geology, geomorphology, altitude, and soil properties) on some characteristics of the species were determined. Results: The results showed that P. tomentosa was absent in igneous formation while it appeared in conglomerate formation. In addition, among geomorphological units, the best quantitative characteristics of P. tomentosa was belonged to the conglomerate formation-small hill area (plant aerial parts = 57.63 and root length = 30.68 cm) with the highest electrical conductivity, silt, and $CaCO_3$ content. Conversely, the species was not found in the mountainous area with igneous formation. Moreover, plant density, length of roots, and aerial parts of the species were negatively correlated with soil sand, while positive correlation was observed with $CaCO_3$, EC, potassium, and silt content. The maximum entropy was found to be a reliable method (ROC = 0.91) for predicting suitable habitats for P. tomentosa. Conclusion: These results suggest that in evaluating the plant's habitat suitability in arid regions, contrary to the importance of the topography, some environmental variables such as geomorphology and geology can play the main role in rangeland plants' habitat suitability.

Lichen as Bioindicators: Assessing their Response to Heavy Metal Pollution in Their Native Ecosystem

  • Jiho Yang;Soon-Ok Oh;Jae-Seoun Hur
    • Mycobiology
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    • v.51 no.5
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    • pp.343-353
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    • 2023
  • Lichens play crucial roles in the ecosystems, contributing to soil formation and nutrient cycling, and being used in biomonitoring efforts to assess the sustainability of ecosystems including air quality. Previous studies on heavy metal accumulation in lichens have mostly relied on manipulated environments, such as transplanted lichens, leaving us with a dearth of research on how lichens physiologically respond to heavy metal exposure in their natural habitats. To fill this knowledge gap, we investigated lichens from two of South Korea's geographically distant regions, Gangwon Province and Jeju Island, and examined whether difference in ambient heavy metal concentrations could be detected through physiological variables, including chlorophyll damage, lipid oxidation, and protein content. The physiological variables of lichens in response to heavy metals differed according to the collection area: Arsenic exerted a significant impact on chlorophyll degradation and protein content. The degree of fatty acid oxidation in lichens was associated with increased Cu concentrations. Our research highlights the value of lichens as a bioindicator, as we found that even small variations in ambient heavy metal concentrations can be detected in natural lichens. Furthermore, our study sheds light on which physiology variables that can be used as indicators of specific heavy metals, underscoring the potential of lichens for future ecology studies.

Estimation in a Model for Determining the Amount of Carbon in Soil and Measurement of the Influences of the Specific Factors (농경지 토양탄소량 결정모형 추정 및 요인별 영향력 계측)

  • Suh, Jeong-Min;Cho, Jae-Hwan;Son, Beung-Gu;Kang, Jum-Soon;Hong, Chang-Oh;Kim, Woon-Won;Park, Jeong-Ho;Lim, Woo-Taik;Jin, Kyung-Ho
    • Journal of Environmental Science International
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    • v.23 no.11
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    • pp.1827-1833
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    • 2014
  • This study has been carried out to present the valuation system of soil carbon sequestration potentials of soil in accordance with the new climate change scenarios(RCP). For that, by analyzing variation of soil carbon of the each type of agricultural land use, it aims to develop technology to increase the amount of carbon emissions and sequestration. Among the factors which affects the estimation of determining the soil carbon model and influence power after the measurement on soil organic carbon, under the center of a causal relationship between the explanatory variables this study were investigated. Chemical fertilizers (NPK) decreased with increasing the amount of soil organic carbon and as with the first experimental results, when cultivating rice than pepper, the fact that soil organic carbon content increased has been found out. The higher the carbon dioxide concentration, the higher the amount of organic carbon in the soil and this result is reliable under a 10% significance level. On the other hand, soil organic carbon, humus carbon and hot water extractable carbon has been found out that was not affected the soils depth, sames as the result of the first year. The higher concentration of carbon dioxide, the higher carbon content of humus and hot water extractable carbon content. According to IPCC 2006 Guidelines and the new climate change scenario RCP 4.5 and the measurement results of the total amount of soil organic carbon to the crops due to abnormal climate weather, 1% increase in atmospheric carbon dioxide concentration was found to be small when compared to the growing rate of increasing 0.01058% of organic carbon in the soil.

Physiological Characteristics and Death Rate of Planted Trees in Reclaimed Seaside Areas (임해매립지 조경수목의 생리적 특성과 식재수목의 고사율)

  • 박현수;이상석;이상철
    • Journal of the Korean Institute of Landscape Architecture
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    • v.31 no.2
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    • pp.94-101
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    • 2003
  • The purpose of this paper is to analyze the correlation between Death Rate of Trees (DRT) and the Physiological Characteristics of Trees(PCT) in POSCO Gwangyang works, which is a reclaimed area. To analyze the DRT, 15 species of deciduous trees were selected, for example Ulmus davidiana var., Zelkova serrata, Melia azedarach var. etc. Though there were numerous factors to affect the growing of trees, 5 PCT were considered to be main factors, soil salt tolerance, wind salt tolerance, water needs, transplanting difficulty, and nutrient needs. According to two kinds of soil-base: mound and pot area, we tested the relationship between 5 PCT and DRT by use of t-test and multiple regression analysis. The results are as follows. 1. The DRT of Acer palmatum, Cornus kousa, Magnolia kobus, Liriodendron tulipifera, and Albizzia julibrissin were high by more than 20%. On the other hand, Chionanthus retusa, Ulmus davidiana var. japonica Celtis sinensis, and Lagerstroemia indica were low by less than 10% in the DRT and are considered to be species suitable for planting in reclaimed areas. 2. The DRT of trees in pot areas was meaningfully higher than in mound areas; for this reason the mound technique is desirable as a soil-base for planting in reclaimed areas. 3. In the pot area, the independent variables, in the order of soil salt tolerance, wind salt tolerance, transplanting difficulty, had an effect on the DRT more significantly than in mount area. On the other hand, wind salt tolerance and soil salt tolerance affected the DRT in mount areas. This means that soil salt tolerance, wind salt tolerance, and transplanting difficulty have to be considered as significant factors to the DRT. Although the researchers tried to interpret how the PCT affected the DRT in order to analyze the relationship between the two in reclaimed areas, it was neglected at an experimental level. Therefore, future research should work on this aspect in detail.

An Analytical Solution of Progressive Wave-Induced Residual Pore-Water Pressure in Seabed (진행파동장하 해저지반내 잔류간극수압의 해석해)

  • Lee, Kwang-Ho;Kim, Dong-Wook;Kim, Do-Sam;Kim, Tae-Hyung;Kim, Kyu-Han;Ryu, Heung Won
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.27 no.3
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    • pp.159-167
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    • 2015
  • In this paper, the errors found in the existed analytical solutions described the mechanism of residual pore-water pressure accumulation were examined and a new analytical was proposed. The new analytical solution was derived by using a Fourier series expansion and separation of variables was verified by comparison with the existed both analytical and numerical solutions and experimental result. The new analytical solution is very simple that there is no need for numerical integration for deep soil thickness. In addition, the solutions of the residual pore-water pressure for finite, deep, and shallow soil thickness reveled that it is possible to approach from finite to shallow soil thickness, but not possible to deep soil thickness because there was discontinues zone between finite and deep soil thickness.