• Korean Journal of Environment and Ecology
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• v.17 no.4
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• pp.360-365
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• 2004

This study was carried out to estimate net fine root carbon production in Quercus variabilis natural stands in Chungiu area. Soil samples were taken in 0-30cm, 30-60cm, and 60-90cm soil depths from April to November using soil sampler. Fine root carbon biomass was higher in 0-30cm soil depth than the other soil depths. Net fine root carbon production (kg/㏊/yr) were 671kg in 0-30cm soil depth, 599kg in 30-60cm soil depth, and 479kg in 60-90cm soil depth, and 1749kg in 0-90cm soil depth. fine root turnover rates were 0.43 in 0-30cm soil depth, 0.96 in 30-60cmsoil depth, and 1.03 in 60-90cm soil depth. N, p, K, and Mg input into the soil (kg/㏊/yr) due to fine root turnover at 0-90cm soil depth in this study were 33.9kg, 1.8kg, 11.4kg and 20.1kg, respectively.

• The Korean Journal of Ecology
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• v.2 no.1
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• pp.31-37
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• 1978

The salt accumulation on the soil surface can be mathematically described. Although the movement of salts in soil solution is expressed in terms of mathematical model, which has certain limitations in practical application, except the exchangeable and absorbable state salts in soil solution. This model is illustrated by analyticl experiments in which evaporation from the bare soils, transpiration of plants and rainfall are required. Agreement between the model and the measured data was satisfactory, which validating the salt accumulation theory on the soil surface.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.247-254
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• 2015

Changes in land-use type can affect soil and water properties in stream ecosystems. This study examined the effects of different land-use types on biogeochemical properties and microbial activities of a stream. We collected water and sediment samples in a stream at three different sites surrounded by varying land-use types; a forest, a radish field and a rice paddy. Nitrogen contents, such as nitrate, nitrite and total nitrogen in the stream water body, showed significant differences among the sampling sites. The highest nitrogen values were recorded at the site surrounded by cropland, as fertilizer runoff impacted the stream. Soil organic matter content in the sediment showed significant differences among sites, with the highest content exhibited at the forest mouth site. These differences might be due to the organic matter in surrounding terrestrial ecosystems. Microbial activities determined by extracellular enzyme activities showed similar values throughout all sites in the water body; however, the activities in the sediments exhibited the highest values near the forest site and mirrored the soil organic matter content values. From these results, we conclude that different land-use types are important factors affecting water and sediment properties in stream ecosystems.

• Environmental Engineering Research
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• v.21 no.3
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• pp.304-310
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• 2016

Removal of arsenic (As) from soil aggregates with particle sizes of > 2.0, 2.0-0.25, 0.25-0.053, < 0.053 mm by soil washing of $KH_2PO_4$ and the kinetics of As releasing from soil aggregates were investigated. Effects of $KH_2PO_4$ concentration, ratio of liquid/soil and washing duration on the removal were fully explored. The results showed that the high As removal was obtained in > 2 mm aggregates (48.56%) and < 0.053 mm aggregates (42.88%) under the optimum condition ($KH_2PO_4$ concentration of 0.1 mol/L, and liquid/soil ratio (10 mL/g) for 360 min). 62.82% of As was extracted from aggregates with size less than 0.25 mm. Only 11.88% was contributed by the large aggregates (> 2.0mm). Using $KH_2PO_4$ washing, it was also found that extracted As is mainly in form of either specifically sorbed As or As associated with oxides of Fe and Al. Elovich model can describe the removal process of As more precisely than Two-constant kinetic models. The optimum washing conditions and removal process is also applied to bulk soil. This technique in this study is reliable, cost-effective and offers a great potential for practical application in soil remediation.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2010.10a
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• pp.204-207
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• 2010

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2010.10a
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• pp.169-173
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• 2010

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2007.10a
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• pp.32-35
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• 2007

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2008.10a
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• pp.140-142
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• 2008

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2010.04a
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• pp.213-216
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• 2010

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2010.04a
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• pp.241-244
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• 2010