• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.447-447
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• 2023

Soil organic carbon (SOC) is a critical indicator of soil fertility. Its importance in maintaining ecological balance has received widespread attention. However, global temperatures have risen by 0.8℃ since the late 1800s due to human-induced greenhouse gas emissions, resulting in severe disruptions in SOC dynamics. To study the impacts of temperature variations on SOC and soil respiration, we used the Soil Carbon and Landscape co-Evolution (SCALE) model, which was capable of estimating the spatial distribution of soil carbon dynamics. The study site was located at Heshan Farm (125°20'10.5"E, 49°00'23.1"N), Nenjiang County in Heilongjiang Province, Northeast China. We validated the model using observed soil organic carbon and soil respiration in 2015 and achieved excellent agreement between observed and modeled variables. Our results showed considerable influences of temperature increases on SOC and soil respiration rates at both erosion and deposition areas. In particular, changes in SOC and soil respiration at the deposition area were greater than at the erosion area. Our study highlights that the impacts of temperature elevations are considerably dependent on soil erosion and deposition processes. Thus, it is important to implement effective soil conservation strategies to maintain soil fertility under global warming.

• Journal of Soil and Groundwater Environment
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• v.14 no.5
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• pp.1-4
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• 2009

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.511-514
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• 2012

Polyethylene mulches have been used for weed control in vegetable production in Korea. One of the additional benefits associated with polyethylene mulches is soil warming. The objective of this study was to evaluate the effects of colored mulches on soil temperature change and Chinese cabbage yield. Mulch treatments were green (GV), black (BV), transparent (TV), and non-mulched (NM) soil. The highest soil-warming effect occurred under green mulch, and the lowest effect was found under black mulch. Daily mean values of soil temperature (10 cm depth) under GV were $2^{\circ}C$ higher than in NM soil. At midday (16:00), mean soil temperature was higher by $3.9^{\circ}C$ in GV, $3.1^{\circ}C$ in BV, and $2.1^{\circ}C$ in TV as compared to NM soil. At night (20:00-06:00), there was no significant difference in soil temperature among the treatments of different colored mulch, but soils in the mulch treatments were $2.4^{\circ}C$ higher as compared to NM soil. As compared with NM, the yield of Chinese cabbage under GV, BV, and TV were higher by 6.0, 26.0, and 12.0%, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.3
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• pp.259-264
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• 2016

The effect of biochar application on soil physics and nitrous oxide ($N_2O$) emission from upland soil for broccoli cultivation was investigated. Sesame straw biochar (SB) was applied at amounts 0 (IF), 50 (SB50), 100 (SB100), 200 (SB200) kg $10a^{-1}$, respectively. SB addition to the upland soil decreased bulk density, and increased porosity and soil respiration. The $N_2O$ emission rates in all treatments were higher in the order of IF $${\geq_-}$$ SB50 > SB100 $${\geq_-}$$ SB200 treatments. Global warming potential in SB200 treatment decreased by 15.1% compared to IF treatment. Therefore, SB application in upland soil can improve soil physics and reduce $N_2O$ emission.

• Journal of the Korean association of regional geographers
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• v.12 no.4
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• pp.437-448
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• 2006

Bare-topped thufur is called as frost scars, implying the rupturing stage of vegetated mounds, Field observations and measurements provide empirical information on the process and factors of thufur disintegration in Mt. Halla, Initial bare patches on mound apexes are scaled up by continuous removal of soil and vegetation, resulting in the formation of crater-like thufur, Frost action plays a primary role in thufur disintegration, In particular, pipkrake loosens soil particles within the bare patches and subsequently accelerates the degradation of vegetated mounds during periods with frequent diurnal freeze-thaw cycle and high soil moisture, Deflation also has an impact on thufur breakup in that the bare patches usually lack upper dark brown soil and are covered with granules, Withered shrubs such as Juniperus chinensis var. sargentii are frequently observed in frost scars and disrupted mounds, indicating that thufur disintegration has been probably influenced by global warming.

• Journal of Korean Society on Water Environment
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• v.27 no.1
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• pp.115-119
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• 2011

The mobility of groundwater in the soil environment has an important role in the soil environment and absorption of plant. Therefore, studies on the mobility of groundwater considering the physical and chemical properties of soil is very important. In this study, movement of water due to change in soil particle size were observed by capillary rise. The height of the capillaries was measured according to capillary diameter, temperature and solution concentration. The inner diameter of each capillary itself is 0.012, 0.016, 0.024, 0.027 cm, and experiments were performed at $22^{\circ}C$. As a result, the height of the capillaries decreased with increasing capillary diameter, and the solution temperature but increased with increasing concentration. Changes in the height of the capillaries are interpreted to related with surface tension by the Young-Laplace equation. Also on the mobility of groundwater, the increase of water and soil temperatures can be significant factors caused by ion strength and global warming as well as pores in the soil particles. The results of this study is considered to provide the basic data on the behavior of groundwater in the soil environment.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.5
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• pp.351-355
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• 2014

In recent years, biochar has received much attention as soil amendment, enhancing soil fertility and reducing toxicity of heavy metals with its large specific surface area and high pH. Biochar has also the effect of alleviating global warming by carbon sequestration from recycling organic wastes by pyrolysis. However, scattering of fine particles of biochar is a hindrance to expand its use from human health point-of-view. Alginate, a natural polymer without toxicity, has been used for capsulation and hydrogel fabrication due to its cross-linking nature with calcium ion. In this study, the method of cross-linkage between alginate and calcium ion was employed for making dust-free biochar bead. Then an equilibrium adsorption experiment was performed for verifying the adsorption effect of biochar bead on heavy metals (cadmium, copper, lead, arsenic, and zinc). Results showed that biochar bead had effects on adsorbing heavy metals, especially lead, except arsenic.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.409-418
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• 2013

Global warming due to climate change is a problem facing the entire world. Several factors, such as $CO_2O$ concentration, level of warming, soil temperature, precipitation, water content of soil and denitrification by denitrifying bacteria influence the emission of nitrous oxide ($N_2O$) from soil. In this study, we investigated nitrous oxide emissions from the soil of two wetlands, Jilmoineup in Mt. Odae and Moojechineup in Mt. Jungjok, according to temperature change. Soil collected in Jilmoineup in July showed increasing $N_2O$ emissions as temperature increases, but did not show any significant differences at $10^{\circ}C$ (p<0.05). Soil of $15^{\circ}C$ and $20^{\circ}C$ showed increasing pattern of $N_2O$ emissions until 24 h. After that, however, there was no difference in temperature. Overall, $N_2O$ emissions showed significant differences according to temperature (p<0.05). Soil collected from Moojechineup in July showed increasing $N_2O$ emissions according to temperature increase, but did not show any significant differences at $10^{\circ}C$ (p<0.05) as was the case for Jilmoineup soil. On the other hand, two wetland soils showed a slight increase of $N_2O$ emissions by additional nitrogen supply, but did not show any significant differences in the presence of nitrogen or between nitrogen sources. In conclusion, increasing temperature the wetland soil increased the emission of $N_2O$, which is a known greenhouse gas. In order to more clearly identify $N_2O$ emissions, various subsequent studies such as the influence and correlation of several factors are required.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.4
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• pp.40-55
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• 2023

Arbor Day is a day that encourages people to plant trees and symbolizes the timing of planting. Arbor Day has been honored on April 5th in Korea, but it often does not agree to actual planting time due to global warming. This study confirmed the discrepancy between Arbor Day and regional soil-thawing times and reviewed alternative dates for tree planting using satellite-based soil-thaw data (FT-ESDR) from 1991 to 2020. Study results showed that the start time of planting on the Korean Peninsula, which was indicated by soil-thaw dates, was March 24 during 1991-2000, and it progressively changed to March 17 during 2011-2020. Should Arbor Day be changed based on soil-thaw periods, mid-March would be the most comprehensive, suitable alternative period considering the number of governmental administration units (cities and counties) and the land area of soil-thaw. Tree-Planting Day (March 14) and International Day of Forests (March 21) were found suitable for alternative dates to Arbor Day because they were close to the average soil-thaw time of Korean Peninsula (March 19) and land area whose soil-thaw time was within 10 days from those two dates ranged from 52.5% to 58.8% centered geographically on the mid-section of the peninsula. Since the periods of soil-thaw will continue to change due to climate change, it is necessary to reflect the trend of advancing planting periods in the future if Arbor Day is changed to an earlier date.

• Journal of Climate Change Research
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• v.7 no.1
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• pp.77-84
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• 2016

Seedling stage is particularly important for tree survival and is easily influenced by warming. Therefore, air temperature being increased due to climate change may affect physiological traits and growth of seedlings. This study was conducted to investigate the physiological and growth responses of Larix kaempferi seedlings to open-field experimental warming. 1-year-old and 2-year-old L. kaempferi seedlings were warmed with infrared lamps since April 2015 and April 2014, respectively. The seedlings in the warmed plots were warmed to maintain the air temperature to be $3^{\circ}C$ higher than that of the control plots. Physiological responses (stomatal conductance, transpiration rate, net photosynthetic rate and total chlorophyll content) and growth responses (root collar diameter (RCD), height and biomass) to experimental warming were measured. Physiological and growth responses varied with the seedling ages. For 2-year-old L. kaempferi seedlings, stomatal conductance, transpiration rate and net photosynthetic rate decreased following the warming treatment, whereas there were no changes for 1-year-old L. kaempferi seedlings. Meanwhile, total chlorophyll content was higher in warmed plots regardless of the seedling ages. Net photosynthetic rate linked with stomatal conductance also decreased due to the drought stress and decrease of photosynthetic efficiency. In response to warming, RCD, height and biomass did not show significant differences between the treatments. It seems that the growth responses were not affected as much as physiological responses were, since the physiological responses were not consistent, nor the warming treatment period was enough to have significant results. In addition, multifactorial experiments considering the impact of decreased soil moisture resulting from elevated temperatures is needed to explicate the impacts of a wide range of possible climate change scenarios.