• 한국환경복원기술학회지
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• 제17권1호
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• pp.13-25
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• 2014

The study aims to investigate and analyze actual situations of managing topsoil at forest development sites based on their types, in pursuit of conservation and effective use of national land. To do this, I selected target areas by deducting the typical types of forest development and analyzed the condition of soil at the target areas before and after development. In addition to this, I interviewed associated construction staffs to conduct study on present situations of topsoil management and find out its problems. I also surveyed of relevant experts, with the intention of seeking solutions. The results of the study have been shown that firstly, experts preferred collecting and recycling of topsoil as methods of improvement of soil conditions for plant growth. Secondly, the importance of topsoil has been well noticed and there were few construction sites using the methods. However, working and economical problems have disturbed carrying out these solutions. Thirdly, after constructions, organic matter and total-nitrogen content decreased in general which were necessary for plant growth in terms of soil conditions.

• Journal of Forest and Environmental Science
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• 제32권2호
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• pp.196-204
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• 2016

In this study, vegetation succession and the rate of consequent topsoil development were investigated in shallow landslide scars of sedimentary rock slopes covered by volcanic ashes and pumice in Kagoshima prefecture, Japan. Seven shallow landslide scars of different ages were selected as study areas. In the initial period after the occurrence of a shallow landslide, deciduous broad-leaved trees such as Mallotus japonicus or Callicarpa mollis were occupied in the areas. Approximately 30 years after the landslide, evergreen broad-leaved trees such as Cinnamomum japonicum invaded in the areas, already existed present deciduous broad-leaved trees. After 50 years, the summit of the canopy comprised evergreen broad-leaved trees such as Castanopsis cuspidata var. sieboldii and Machilus thunbergii. Moreover, the diversity of vegetation invading the site reached the maximum after 15 years, followed by a decrease and stability in the number of trees. The total basal areas under vegetation increased with time. It was concluded that the vegetation community reaches the climax stage approximately 50 years after the occurrence of a shallow landslide in the study areas, in terms of the Fisher-Williams index of diversity (${\alpha}$) and the prevalence of evergreen broad-leaved trees. Moreover, according to the results of topsoil measurement in the study areas, the topsoil was formed at the rate of 0.31 cm/year. The development of topsoil usually functions to improve the multi-faceted functions of a forest. However, when the increased depth of topsoil exceeds the stability threshold, the conditions for a shallow landslide occurrence are satisfied. Therefore, we indicated to control the depth of topsoil and strengthen its resistance by forest management in order to restrain the occurrence of shallow landslides.

• 한국조경학회지
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• 제41권1호
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• pp.34-43
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• 2013

이 연구의 목적은 표토보존을 위해 국내 개발분야 중 주요한 사례에 해당하는 하천개발분야에서 표토관리의 실태를 조사 및 분석하는 데 있다. 전문가를 대상으로 한 설문조사를 통해 하천개발과정에서 표토관리의 실태와 문제를 파악하였다. 이를 분명히 하기 위해 국내 하천개선사업 중 환경부의 감독을 받는 생태하천복원사업으로서 최근 완료된 하천을 중심으로 개발 전과 개발 후의 토양특성을 분석하였다. 연구 결과는 다음과 같다. 첫째, 전문가들은 식물생장을 위해 최선의 토양관리 및 개선방법으로서 표토의 수거 및 재활용을 선호하였다. 둘째, 경제적 문제와 시공의 불편 때문에 실제 표토의 수거 및 재활용은 제대로 이루어지고 있지 않다. 셋째, 개발 후 식물생장에 필요한 유기물, 총질소 등 토양조건 요인들이 전반적으로 감소한다.

• 한국토양비료학회지
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• 제48권5호
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• pp.351-360
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• 2015

Human influence on soil formation has dramatically increased with human civilization and industry development. Increase of anthropogenic soils induced researches on the anthropogenic soils; classification, chemical and physical characteristics of anthropogenic soils and plant growth from anthropogenic soils. However there have been no comprehensive analyses on soil pore or physical properties of anthropogenic soils from 3 dimensional images in Korea. The objectives of this study were to characterize physical properties of anthropogenic paddy field soils by depth and to find differences between natural and anthropogenic paddy field soils. Soil samples were taken from two anthropogenic and natural paddy field soils; anthropogenic (A_c) and natural (N_c) paddy soils with topsoil of coarse texture and anthropogenic (A_f) and natural (N_f) paddy soils with topsoil of fine texture. The anthropogenic paddy fields were reestablished during the Arable Land Remodeling Project from 2011 to 2012 and continued rice farming after the project. Natural paddy fields had no artificial changes or disturbance in soil layers up to 1m depth. Samples were taken at three different depths and analyzed for routine physical properties (texture, bulk density, etc.) and pore properties with computer tomography (CT) scans. The CT scan provided 3 dimensional images at resolution of 0.01 mm to calculate pore radius size, length, and tortuosity of soil pores. Fractal and configuration entropy analyses were applied to quantify pore structure and analyze spatial distribution of pores within soil images. The results of measured physical properties showed no clear trend or significant differences across depths or sites from all samples, except the properties from topsoils. The results of pore morphology and spatial distribution analyses provided detailed information of pores affected by human influences. Pore length and size showed significant decrease in anthropogenic soils. Especially, pores of A_c had great decrease in length compared to N_c. Fractal and entropy analyses showed clear changes of pore distributions across sites. The topsoil layer of A_c showed more degradation of pore structure than that of N_c, while pores of A_f topsoil did not show significant degradation compared with those of N_f. These results concluded that anthropogenic soils with coarse texture may have more effects on pore properties than ones with fine texture. The reestablished paddy fields may need more fundamental remediation to improve physical conditions.

• 지질공학
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• 제33권1호
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• pp.69-83
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• 2023

산불 피해지는 수목 및 식생 전소, 산지토양 황폐화 등으로 인해 산사태주의보 기준에 미치지 못하는 강우조건에서도 토사 세굴 및 유출로 인한 산사태와 토석류 등의 2차 피해 위험을 증가시킨다. 산불은 지표 식생과 토양 특성의 변화를 발생시켜 산불 피해지 내에서 유출량 변화에 큰 영향을 주기 때문이다. 즉, 산불은 토양의 중요한 물리, 화학적 특성 변화로 인해 토양조성 변화, 구성광물의 변화, 토양수의 반발성, 토양 덩어리의 안정성이나 토양 조직의 변화를 발생시킨다. 특히, 산불 발생 및 확산 과정에서는 토층의 유기물과 수목의 연소 외에도 지표면 또는 지표면 아래까지 열기가 전파되어 토층을 구성하고 있는 토양 광물에 영향을 주게 된다. 이에 본 연구에서는 산불 발생지와 미발생지에서 채취된 토양시료(Topsoil, Subsoil)에 대해 XRD 회절분석 및 토양 물성분석을 통해 토양 내 점토광물의 분포와 함양 특성을 파악하였다. 그 결과, 산불 발생지의 토양시료에서 뮬라이트, 아날사이트, 적철석 등이 소량 산출되었으며, 버미큘라이트, 일라이트/버미큘라이트 혼합층상 구조광물(I/V)은 특히 표토에서 특징적으로 산출되었다. 특히, 산불 발생지에서는 일라이트/버미큘라이트 혼합층상 구조 광물(I/V)이 특징적으로 확인되었으나, 산불 미발생지에서는 일라이트/버미큘라이트(I/S) 혼합층상 구조 광물은 산출되지 않아 산불 발생지의 토양과는 큰 차이를 보인다. 이와 같이 점토광물의 생성은 외적요인인 산불의 영향으로 인해 토양 내 광물 조성의 변화를 파악할 수 있었다. 팽창성 점토광물은 우기 시에 토층 내에서 흙의 체적을 팽창시키기 때문에 장기적으로 사면 지반의 구조적 안정성에 영향을 줄 수 있어, 산불 발생지의 토층에서 점토광물의 생성은 장기적으로 산지사면 안정성에 영향을 줄 수 있을 것으로 판단된다.

• 한국환경과학회지
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• 제28권12호
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• pp.1061-1069
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• 2019

Common reed (Phragmites australis) is widespread in reclaimed land and wetland habitats. Every year, the common reed produces extensive colonies by means of underground rhizomes and ground-surface stolons. From an agricultural point of view, the common reed's large biomass is a good material for supplying organic matter. However, it has not yet been studied in terms of seedling production, transplanting conditions, and decomposition characteristics in reclaimed land. Seeds were harvested from the native common reed in Saemangeum, South Korea, the previous year and stored on an open field. The seeds were sowed in the greenhouse at the beginning of April. Common reed decomposition was studied from June to September, with the use of coarse mesh (5 mm) stem litterbags, on three samping dates and with five replicate packs per sample. These packs were dug in five soil condition (low-salinity topsoil, subsoil, high-salinity topsoil, subsoil, paddy topsoil) to 0.2 m and 0.4 m depth. The highest germination rate of common reed seeds was observed in non-salt solution, but the exhibited germination rate was 70% at 9.38 dS m^-1. The plant height of young reed decreased steadily with increasing salinity, but leaf number did not decrease by 9.38 dS m^-1. The survival rate of the two-year-old reed was 83.3%, which was 35% higher than that of the one-year reed. The transplant success rate was 0% in the no vinyl mulching in the soil, but the first year and second year seedlings survived rates were 63% and 83.3%, respectively, in vinyl mulching. Common reed decomposition rates were faster low salinity than high salinity. All nutrient contents were found to fluctuate significantly with time by soil conditions. We also need to study the growth rate of reed transplanting seedlings by soil moisture contents and the comparison of degradation in common reed tissues.

• Journal of Microbiology and Biotechnology
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• 제24권6호
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• pp.843-853
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• 2014

In the context of artificial groundwater recharge, a reactive soil column at pilot-scale (4.5 m depth and 3 m in diameter) fed by treated wastewater was designed to evaluate soil filtration ability. Here, as a part of this project, the impact of treated wastewater filtration on soil bacterial communities and the soil's biological ability for wastewater treatment as well as the relevance of the use of multi-bioindicators were studied as a function of depth and time. Biomass; bacterial 16S rRNA gene diversity fingerprints; potential nitrifying, denitrifying, and sulfate-reducing activities; and functional gene (amo, nir, nar, and dsr) detection were analyzed to highlight the real and potential microbial activity and diversity within the soil column. These bioindicators show that topsoil (0 to 20 cm depth) was the more active and the more impacted by treated wastewater filtration. Nitrification was the main activity in the pilot. No sulfate-reducing activity or dsr genes were detected during the first 6 months of wastewater application. Denitrification was also absent, but genes of denitrifying bacteria were detected, suggesting that the denitrifying process may occur rapidly if adequate chemical conditions are favored within the soil column. Results also underline that a dry period (20 days without any wastewater supply) significantly impacted soil bacterial diversity, leading to a decrease of enzyme activities and biomass. Finally, our work shows that treated wastewater filtration leads to a modification of the bacterial genetic and functional structures in topsoil.

• 한국환경생태학회지
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• 제11권1호
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• pp.37-45
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• 1997

지리산국립공원 노고단 지역에 분포하는 아고산대 초원지역은 급증한 이용객들에 의해 훼손되고 있다. 교란된 아고산대 초원지역의 복원공법을 개발하기 위한 기초연구로서, 이 지역에 시비처리, 식생도입처리, 멀칭처리를 각각 2수준으로 한 2*2*2 요인 실험을 표토가 유실된 10% 경사지와 표토가 잔존하는 40% 경사지에 실시하였다. 그 결과, 부지조건에 관계없이 야생풀포기심기가 파종보다 식생활착에 있어 더 효율적이었고 시비처리는 출현개체수와 피복도 증가에 통계적 유의성을 나타냈다. 반면 식생활착에 미치는 멀칭재료간 효과는 유의성이 없었다. 한편 척박지의 선구수종으로 추정되는 개쑥부쟁이는 직접파종에도 높은 활착율을 보였다.

• 한국농공학회지
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• 제17권3호
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• pp.3860-3871
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• 1975

This experiment was carried out to establish the mechanized methods in stumping and root-clearing, which were the most important works in the reclamation of sloping uplands. The determination of optimum teeth interval of rake blades and its operation methods to reduce the quantity of transported topsoil during the works, are the aims of this investigation. A newly designed rake blade, whose net teeth intervals could be regulated by three stages as 15cm, 25cm, and 35cm, was manufactured to attach to the bulldozer of 13ton. The experiments were carried out at Kilsang-Myon, Kwangwha-Gun, from Aug. 9 to Aug. 23, 1975. For each interval, 36 test plots of 50${\times}$10mn in size, which were regulated under three levels of land slopes of 10, 20, and 30% and two different tree stand density of high or medium values, were randomly chosen and arranged by two-replicated split-split plot design. Each stump classified by its diameter was stumped and cleared by the rake dozer to be related between diameter and stumping time. The results obtained in this experiment can be summarized as follows: 1. Stumping times for the diameters ranging from 6 to 18cm of stumps are almost the same and they are not varied by the difference of teeth intervals of rake dozer. 2. By back-ward stumping method, the number of stumps which can be stumped per hour ranges almost from 100 to 170, showing significant difference with respect to the teeth intervals. The working area is sharply varied with not only the stand density of stumps but the teeth intervals. 3. Optimum stumping distance for each teeth interval of rake dozer to minimize the quantity of transported topsoil are varied with such the rates as it is 15m or 20m for 15cm of teeth interval, but 25m for 25cm or 35cm, respectively. The clearing distance could be chosen almost double as long as the operating distance. 4. The working areas per hour of the simultaneous stumping and clearing methods are no significant difference among the various treatments of working conditions, but they are affected by the operating techniques. However, the influencing factors of the working conditions as classified before and the working directions are ranged from 10 to 15 per cent of total working area, respectively. 5. The residual rates of stumps which are not stumped by the rake dozer in each test plot are generally reduced as the teeth interval gets narrower, but there are no significant difference among them. The mean residual rates average to be about 4% for the simultaneous stumping and clearing method. The back-ward stumping method are recommended to be supervised and directed by more than one man, to show the operator where the stumps are located. 6. The results according to the stumping and clearing methods are summarized as Table IV-2. And the selection of working methods is recommended to follow as shown in Fig. IV-9 with respect to the stand density of the field. 7. Generally speaking, the narrower the teeth interval, the better become the working results, but the more the quantity of transported topsoil is increased. Therefore, it is recommended that the teeth interval should be reduced from the present distance of more than 30cm to 25cm or 15cm, by developing suitable working methods through more field works and experiments.

• 한국토양비료학회지
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• 제27권3호
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• pp.189-194
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• 1994

신개간경사지(新開墾傾斜地)에서 생산력 증대를 위한 물리화학적인 개량방법(改良方法)과 고구마 재배에 대한 기초자료를 얻고자 1985년부터 4년간 송정양토(松汀壤土)에서 고구마를 재배하면서 토양물리화학성의 년차간(年次間) 변화량(變化量)과 변화율(變化率) 및 고구마의 수량을 조사, 분석하였다. 1. 토양의 용적밀도는 토심(土深)에 관계없이 2년차부터 계속 높아졌으나 경도(硬度)는 표토에서는 같은 경향이나 심토에서는 일정한 경향이 없었다. 2. 고구마의 4년간 평균수량(平均收量)은 종합개량구(綜合改良區)에서 32.68ton/ha으로 제일 많았고 대조구(對照區)에 비해 59% 증수(增收)되었으며 처리별로는 인산구>심경구>석회구>퇴비구>대조구 순으로 많았다. 3. 년차간(年次間) 고구마 수량과 토양의 물리화학성과의 상관계수는 표토에서는 용적밀도, 경도, 양이온치환용량과 심토에서는 용적밀도, 토양수분, 양이온치환용량과 유의성이 높았다. 4. 토양의 물리화학성 변화률(變化率)과 고구마 수량(收量)과의 상관관계(相關關係)는 유기물 함량을 제외한 다른 특성과 유의성이 있었고 개량제(改良劑) 시용(施用)이 없었던 4년차에 토양(土壤)의 물리화학성(物理化學性)이 악화(惡化)되었음을 알 수 있었다.