• Korean Journal of Environmental Biology
• /
• v.17 no.4
• /
• pp.421-426
• /
• 1999

Species composition, species diversity, standing biomass and soil properties of the grasslands, which are developed in the vicinity of Yoch’on Industrial Complex, were investigated. The grassland divided into three types, mugwort (Artemisia princeps var. orientalis) community, porkweed (Phytolacca americana) community and eulalia (Miscanthus sinensis) community by physiognomy Standing biomass of mugwort community, porkweed community and eulalia community was 5,645 g/$m^2$, 2,827 g/$m^2$ and 9,048 g/$m^2$, respectively. Species diversity of mugwort community, porkweed community and eulalia community was 1.03, 0.54 and 0.26, respectively. Total N, available P, total S and soluble S of the top soil in this grassland were much higher than those in other areas. Most of the species in this grassland are indicator species of soil eutrophication.

• Journal of Bio-Environment Control
• /
• v.18 no.4
• /
• pp.316-325
• /
• 2009

Adequate conditions of water content and aeration of container media are major environmental factors in the production of pot plant. This experiment was carried out to find optimum physical property of media for the production of small potted Ardisia in capillary mat irrigation system. The plant materials used in this experiment were Ardisia pusilla and Ardisia japonica. Seven substrates were formulated by blending perlite or fresh rice hulls at 20%, 40%, 60% (v/v) with sphagnum peat. Total pore space (TPS) increased by blending sphagnum peat with fresh rice hulls, but decreased by blending sphagnum peat with perlite. As fresh rice hull (FRH) and perlite content increased, air filled pore space (AFP) of substrate increased but container capacity (CC) decreased. Substrate blended with fresh rice hull was higher AFP than blended with perlite and the rate of increase was higher for FRH-containing substrate. As AFP increased, the $CO_2$ concentration in the pot decreased and the $CO_2$ concentration of substrate blended with FRH was higher than blended with perlite. The fresh and dry weight of Ardisia pusilla and A. japonica was the highest in the substrate contained 60% FRH, but the ratio of shoot dry weight to root dry weight was the lowest. The optimum total pore space, air-filled pore space, water holding capacity of substrate for the growth of Ardisia pusilla and A. japonica in the capillary mat irrigation system were 82.8%, 25.6%, and 57.2% respectively.

• Korean Journal of Environmental Biology
• /
• v.36 no.1
• /
• pp.50-61
• /
• 2018

The current study aimed to review the research trends on forest liming by age, country, and research topics, and seeks to summarize the effects of forest liming on soil, vegetation and water system in forest ecosystems. The recent goals of forest liming have been changed in response to changes in the acid deposition, and related studies have been mainly carried out in Europe and North America, where there is noted a massive forest decline, which was subsequently caused by acid rain. Most forest liming studies are noted to have focused on soil responses, however, the number of studies on the responses of vegetation and water system according to a literature review on the subject were relatively small. Meanwhile, forest liming influenced whole forest ecosystems through interaction between the soil, vegetation and water system as associated with the relevant regions. The changes in soil pH, base saturation, and cation exchange capacity by forest liming were noted as different depending on the soil layer and elapsed time after liming. The responses of vegetation to forest liming were shown in above- and below-ground plant growth and plant nutrient concentration, and also were noted to have varied depending on the available regional plant species and noted specific soil conditions. The chemical properties of the water system were changed similarly to those in the soil, leading to notable changes as seen in the planktons and available fish species in the region. Finally, these results could be used to plan further studies on forest liming, which would significantly benefit regional studies to promote the preservation of the species noted for protection in the region.

• Journal of Korean Society of Forest Science
• /
• v.102 no.4
• /
• pp.522-529
• /
• 2013

Climate change will affect the physiological traits and growth of forest trees. This study was conducted to investigate the effects of an experimental warming on growth and physiological characteristics of Pinus densiflora S. et Z. seedlings. One-year-old P. densiflora seedlings were planted in control and warmed plots in April 2010. The air temperature of warmed plots was increased by $3^{\circ}C$ using infrared lamps from November 2010. We measured shoot height, root collar diameter, above and below ground biomass, chlorophyll contents and leaf nitrogen concentration from March 2011 to March 2013. Seedling height and root collar diameter showed no significant difference between warmed and control plots except for root collar diameter measured in June 2012. Seedling leaf biomass was lower in the warmed ($23.94{\pm}2.10g$) than in the control ($26.08{\pm}1.72g$) plots in 2013. Shoot to root ratio (S/R ratio) was lower in the warmed ($1.09{\pm}0.07$) than in the control ($1.31{\pm}0.10$) plots in 2013. Leaf nitrogen concentrations and chlorophyll contents were not significantly different between warmed and control plots except for leaf nitrogen concentration in 2011. Leaf C/N ratio was increased in 2012 under the warming treatment. Low growth and S/R ratio in warmed plots might be related to the higher temperature and water stress. In the future, the below-ground carbon allocation of P. densiflora might be increased by global warming due to temperature and water stress.

• Korean Journal of Environmental Biology
• /
• v.17 no.4
• /
• pp.449-457
• /
• 1999

Removal efficiency and potential of N and P by Salix gracilistyla Miq. are determined in continuous flow tanks as a function of hydraulic retention time (HRT, days) and nutrient concentration (NC). Results show that the removal efficiency was longer HRT and lower nutrient solution. And also removal potential was higher at shorter HRT and higher nutrient concentration, and the regression equations were estimated. Mean above ground biomass of Salix gracilistyla Miq. in the middle reaches of Suip stream was 4880.81 g/$m^2$, and estimated removal by this vegetation from biomass and estimated equation above were 0.49~15.49 NH$_4$-N kg/day, 5.83~405.39 NO$_3$-N kg/day, 7.57~23.22 PO$_4$-P kg/day in Suip stream, respectively when HRT was 0.59~5.21, inflow concentration was 0.05~0.4, mg/L NH$_4$-N, 1.42~11.36 mg/L NO$_3$-N, 0.1~0.27 mg/L PO$_4$-P. According to this study, it is concluded that Salix gracilistyla Miq. are contribute by their high biomass and for water quality improvement of stream through nutrient removal potential.

• Korean Journal of Environmental Agriculture
• /
• v.35 no.4
• /
• pp.278-285
• /
• 2016

BACKGROUND: Uptake patterns of ${\alpha}$-, ${\beta}$-isomers and sulfate metabolite of endosulfan (ED) by radishes grown in treated soils with ED concentrations of 2 and 10 mg/kg were investigated to establish soil management guidelines for ensuring the safety of radishes from ED residues. METHODS AND RESULTS: All samples of soils and radish plants separated into shoot and root parts were analyzed for ED residues using a gas-chromatography mass spectrophotometer, and the results were used to calculate the bioconcentration factor (BCF), indicating the ratio of ED concentrations between radishes and soils. During the experimental period, uptake and distribution rates of ED-sulfate in radishes were the highest, followed by ${\alpha}$- and ${\beta}$-ED. The BCF values to initial ED concentrations in soils were greater for root parts (0.0077 to 0.2345) than for shoot parts (0.0002 to 0.0429) and used to obtain regression equations by time. Long-term BCFs estimated by the obtained equations ($R^2$ of 0.86 to 1.00) were evaluated with the maximum residue limit (0.1 mg/kg) of ED for radishes, in order to suggest safe management guidelines of ED for radish-cultivating soils. CONCLUSION: Suggested guidelines showed the significant dependency on duration for radish cultivation and exposed concentration of ED in soil.

• Journal of Bio-Environment Control
• /
• v.16 no.1
• /
• pp.7-12
• /
• 2007

This study was conducted to clarify the effects of the different concentration of the nutrient solution on the early growth and the nutritional contents of hydroponically grown Aster koraiensis, Hemerocallis fulva and Plantago asiatica at 70 days after transplanting in perlite culture. Balanced nutrient solution formulated by Japanese Horticultural Experiment Station was used as the standard concentration of the nutrient solution. Overall plant growth of Aster koraiensis and Hemerocallis fulva such as plant height, stem diameter, number of loaves, fresh and dry shoot and root weight were significantly increased in 1.5 times concentration of nutrient solution. Shoot and root fresh and dry weight of hydroponically grown Plantago asiatica were significantly increased in the higher concentration of the nutrient solution, however, number of loaves and root length were significantly increased in the standard and the lower concentration of the nutrient solution. The highest contents of calcium, magnesium and sodium in plants were shown in Aster koraienxis which were grown in the 1.5 times concentration of nutrient solution, and Hemerocallis fulva and Plantago asiatica in 0.25 times of that. The contents of potassium in Aster koraiensis and Hemerocallis fulva were significantly increased when the plants were grown in the 0.5 times concentration of the nutrient solution, and that in Plantago asiatica in the 1.5 times concentration of the nutrient solution. The contents of phosphoric acid in plants as affected by the different species of Namul and the different concentration of the nutrient solution were not significant.

• Journal of Bio-Environment Control
• /
• v.20 no.4
• /
• pp.283-289
• /
• 2011

This study was conducted to examine the effects of defoliation treatment on the growth and yield of strawberry ($Fragaria{\times}ananassa$ cv. Maehyang and Seolhyang) during nursery period. Leaves of strawberry plantlet had been removed except two, three and four fully expanded leaves until planting date. As the intensity of defoliation was strong, the petiole length was reduced and overgrowth of strawberry plantlet was suppressed. Outer diameter of crown in defoliation treatments significantly decreased but inner diameter of crown was not significant. Number of primary roots of the 3 leaves or 4 leaves defoliation treatment generally tended to increase, but there was not significantly different among treatments. Fresh weight and leaf area in the defoliation treatments significantly decreased and the root weight were higher in partial 3 leaves or 4 leaves defoliation treatment but was not significantly different among treatments. Because T/R ratio decreased significantly as growth inhibition of above-ground part compared to underground part, it is considered easy to take rooting after plantlet plating. As the intensity of defoliation was strong, chlorophyll contents tended to decrease significantly. Reduction of the endogenous nitrogen by defoliation effectively led to promote floral differentiation at low temperature and short day condition. This promoted timing of budding and flowering and also induced uniform flowering after plantlet planting. Marketable fruit yield of 3 leaves defoliation treatment tended to be higher than the control.

• Journal of Bio-Environment Control
• /
• v.21 no.4
• /
• pp.385-391
• /
• 2012

This study was conducted to investigate the effects of the runner cutting time on the growth and yield of strawberry (Fragaria ${\times}$ ananassa cv. Maehyang and Seolhyang) during nursery period of two consecutive years (2009 and 2010). Strawberry runners which connected from mother plants to daughter plants were cut 30, 20, 10 and 5 days before transplanting day (11 Sep. 2009 and 10 Sep. 2010). When runner cutting time delayed, more nutrition was supplied to the daughter plant until late nursery period. It showed that there was a tendency to increase the fresh weight, crown diameter and leaf chlorophyll content. On the other hand, when the runner was cut earlier, the growth of underground part such as root weight was improved. Irrigation demand increased to 29.7% in case of runner cutting from mother plant compared with runner non-cutting treatment. In addition, infection ratio of anthracnose through runner part was 37.6% higher in case of runner cutting than that of runner non-cutting treatment. After transplanting, budding and flowering period were delayed up to 2 or 3 days because of late runner cutting. But there was no significant difference in marketable fruit yield among runner cutting times. It is recommended to conduct runner cutting 5 or 10 days before transplanting for reducing the occurrence of anthracnose.

• Journal of Bio-Environment Control
• /
• v.29 no.1
• /
• pp.28-35
• /
• 2020

This study is to compare irrigation efficiency between sap flow sensor automated system (SF) and conventional irrigation system based on integrated solar radiation automated system (ISR) in tomato rockwool hydroponics. Total irrigated volumes was higher in the ISR system by 5.0L per plant, a lower drainage rate was found in the SF system, compared to the ISR system. There was no difference in shoot and fruit fresh weights, water use efficiency (WUE) and water amount consumed for producing 200g of tomato fruit. The daily average sap flow density (SFD) was closer to the change of solar irradiance (SI) in the plant grown under the SF system, compared to the ISR system. The correlation coefficient (r²) between the fruit diameter and the volumetric water content during the 56 and 82 days after transplant showed the SF treatment was higher than the ISR at night and daytime, and the correlation was higher at night time. The sap flow density and humidity deficit (HD) of SF treatment was related as closely as the solar irradiance. Further studies should demonstrate that SF irrigation system is a convenient method for hydroponic farmers with advantages, such as growth, higher yield, WUE, and accuracy.