• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.1
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• pp.1-10
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• 2022

This study was conducted to investigate the germination characteristics through the temperature change treatment compared to the general room temperature immersion treatment of the native species, the Larix kaempferi, and the Berula platyphyllavar. japonica seeds, and to obtain basic data for the production of healthy seedlings with high productivity and efficiency. As a result, the germination rate of the larch seeds showed a significant difference according to room temperature and temperature immersion treatment, and the average germination days of the birch seeds showed a significant difference according to room temperature immersion and temperature immersion treatment. On the other hand, there was no significant difference in germinal uniformity. The results of the study are as follows. First, the results of the analysis of the fallen leaves were the highest germination rate in the treatment of 1.5 days of hot water and 1.5 days of cold water, the fastest germination rate, the lowest average germination day, and the highest germination uniformity. This is the best result in most items, and the change temperature immersion treatment of hot and cold baths was superior to the conventional room temperature immersion treatment. Second, the results of birch tree showed that the germination rate was the highest in 1.5 days of hot water and 1.5 days of cold water. The average germination day is 1.5 days of cold water 1.5 days of hot water 1.5 days, but the difference between 1.5 days of hot water and 1.5 days of cold water is 0.01 days. The highest germinated uniformity was found in 1.5 days of cold water and 1.5 days of hot water. As a result, in the case of larch and birch, the seed temperature immersion (1.5 days of hot water, 1.5 days of cold water) treatment is superior to the existing three-day immersion treatment in various analysis methods, and it is expected that productivity and efficiency can be improved at a low cost in a short period of time at the seedling production site through seeds.

• Journal of Environmental Impact Assessment
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• v.31 no.6
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• pp.423-437
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• 2022

Parts of damaged trees are being transplanted in accordance with the Environmental Impact Assessment Manual. Problems such as death or poor growth are constantly being addressed in the process of transplanting trees from the forest they originally inhabited to temporary and final transplant sites. The purpose of this study is to analyze the differences in soil properties in the surrounding forest, the temporary transplant site, and the construction site and to suggest methods for improving the soil to make it suitable for the growth of transplanted trees. For 10 development projects, 2 soil samples were sampled from the surrounding forest, temporary transplant site, and construction site. A total of 60 soil samples were analyzed for physical and chemical properties. Among the physical properties such as coefficient of permeability, available moisture, and hardness, and chemical properties such as acidity, organic matter content, total nitrogen, and available P showed significant differences among groups. The soil of the construction site is harder than the surrounding forest because of construction equipments, the coefficient of permeability is higherthan the surrounding forest because of high sand content, and the available moisture was low. It does not retain the moisture necessary for plants in the soil and drains immediately. It is necessary to implement tillage to improve the physical properties and structure of the soil. In addition, it is necessary to cover the surface with wood chips or fallen leaves after adding mature organic matter to improve the physical and chemical properties of the soil together.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1065-1076
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• 2022

The purpose of this study was to investigate the effect of the expansion and withering of Salix subfragilis communities on the water quality in Namgang Dam reservoir. The distribution area of the Salix subfragilis communities was 0.12 km² in 2003 for the first time, but it was 3.58 km² in 2019, which has increased rapidly by about 30 times in 16 years. However, in 2013, the distribution area has decreased by 0.17 km² due to long-term immersion in high turbidity, and self-thinning in Salix subfragilis communities. The lake characteristics of reservoir showed a combination of lake type and river type in terms of average water depth, watershed area/lake surface area ratio, water residence time, flushing rate, and stratification. From the result of analyzing long-term changes in lake water quality, COD, TP, and chlorophyll-a in Salix subfragilis communities were significantly larger than those in the three points located in the central part of reservoir. In particular, the fact that the value of chlorophyll-a showed the maximum value in winter rather than summer, unlike the trend of the three points in the Namgang Dam water quality monitoring network, is thought to have occurred internally rather than externally. It can be estimated that one cause of this deterioration of the water quality in Namgang Dam reservoir is the huge amount of nutrients generated in the decomposition process of by-products such as fallen leaves, branches and withered trees in Salix subfragilis communities.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.339-347
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• 2023

Dissolved organic matter (DOM) is a key component in the biogeochemical cycling in freshwater ecosystem. However, it has been rarely explored, particularly complex river watershed dominated by natural and anthropogenic sources, such as various effluent facility and livestock. The current research developed a new analytical method for TOC/TN (Total Organic Carbon/Total Nitrogen) stable isotope ratio, and distinguish DOM source using stable isotope value (δ¹³C-DOC) and spectroscopic indices (fluorescence index [FI] and biological index [BIX]). The TOC/TN-IR/MS analytical system was optimized and precision and accuracy were secured using two international standards (IAEA-600 Caffein, IAEA-CH-6 Sucrose). As a result of controlling the instrumental conditions to enable TOC stable isotope analysis even in low-concentration environmental samples (<1 mgC L^-1), the minimum detection limit was improved. The 12 potential DOM source were collected from watershed, which includes top-soils, groundwater, plant group (fallen leaves, riparian plants, suspended algae) and effluent group (pig and cow livestock, agricultural land, urban, industry facility, swine facility and wastewater treatment facilities). As a result of comparing characteristics between 12 sources using spectroscopic indices and δ¹³C-DOC values, it were divided into four groups according to their characteristics as a respective DOM sources. The current study established the TOC/TN stable isotope analyses system for the first time in Korea, and found that spectroscopic indices and δ¹³C-DOC are very useful tool to trace the origin of organic matter in the aquatic environments through library database.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.111-119
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• 2018

This study was carried out to investigate the growth characteristics and propagation methods of the Korean native Amelanchier asiatica, A. arborea, and A. alnifolia as fruit trees for gardens. Due to the lack of recent research on Amelanchier spp., their superficial classification is still unclear and the names are being used interchangeably. The results are obtained as follows : A. arborea and A. alnifolia were globular type multi-stemmed shrubs. A 20-year-old tree of A. asiatica was 7.8m in height, with a 5.2m crown width, with one trunk. As for the morphological characteristics, leaves of A. asiatica were oblong, with an acuminate of, 6.1cm and 3.6cm width, but A. arborea and A. alnifolia had acute obovate leaves. The leaf size of A. alnifolia was the largest among the three species. The flower size of A. asiatica was bigger than that of A. arborea and A. alnifolia. In addition, its petals and flower clusters were also the largest among the three species. The flowering of A. asiatica initiated on April 21 and then bloomed for a duration of 24 days in Osan, while that of A. arborea and A. alnifolia initiated flowering on April 12 and then bloomed for a duration of 22 days in the same location. The fruit of A. arborea and A. alnifolia were green on May 10~12, it changed into purplish red on May 24~26, and its matured on June 1~3. The duration of fruit persistence of A. arborea and A. alnifolia were 48~50 days. On the other hand, A. asiatica showed greenish fruit on May 20, it became red on September 4, and had fallen by October 3. The fruit size was the largest at 1.03cm of height and 1.12cm of diameter in the A. arborea, followed by the big berry of A. alnifolia and the smallest fruit in the native, A. asiatica. It was difficult to root due to the hardwood cutting of A. arborea at a 40% rate of rooting. In the softwood cutting, the rooting rate of A. arborea was increased by the treatment with concentrated IBA, especially at 5,000 and 7,000ppm. The optimum date for cutting was on June 27, when the rooting rate was more than 80%. The most effective method for rooting of A. arborea was rootone or 7,000 ppm IBA treatment on June 27 softwood cuttings, which showed a rooting rate of over 80%.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.500-509
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• 2014

To prevent freezing of the road by fallen snow, Calcium chloride($CaCl_2$) as a deicer is used to very often and it can be harmful to roadside trees. This study was conducted to investigate the effects of Calcium chloride($CaCl_2$) as a deicer on growth and physiological traits of Acer triflorum according to different concentration of $CaCl_2$. We measured growth, chlorophyll contents, gas exchangement characteristics, chlorophyll fluorescence and mineral nutrition concentration in plant and soil. The experimental group was composed of four treatments including 0mM(control), 9mM(0.5 %), 18mM(1.0 %), 54mM(3.0 %). Before germinating new shoot, the dissolution of $CaCl_2$ was irrigated twice interval of a week. At 30 days after treatment, all treatments decreased total cholorophyll content, photosynthetic rate, transpiration rate, stomatal conductance and photochemical efficiency($F_v/F_m$) with increasing concentration of $CaCl_2$ and especially, they significantly reduced in 3.0 % treatment. In contrast, chlorophyll a/b ratio increased with an increase of $CaCl_2$ concentration and water use efficiency increased in 1.0 % and 3.0 % treatments. At 50 days after treatment, all treatments were decreased in chl a, chl b, total chlorophyll content, carotenoid content, photosynthetic capacity, photochemical efficiency($F_v/F_m$) and quantum yield of photosystem II(${\Phi}_{PSII}$) compared with control and 3.0 % treatments were withered. $Ca^{2+}$ and $Cl^-$ were accumulated in leaves and soil, which inhibited water absorption and electron transport and it caused the reduction of height growth rate more than 50 %. Although there was a little difference according to time and $CaCl_2$ concentration, all treatments decreased in growth rate and physiological activity slowed down. As time passed, these results got worse. Therefore we need to take a measure earlier in order to minimize damage of trees.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.2
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• pp.132-139
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• 1999

A field experiment was conducted at Cheju from early March 1998 to early March 1999 to evaluate the effects of foliar applied urea on leaf N content and N recovery in satsuma mandarins (Citrus unshiu Marc.). Seven years old 'Okitsu Wase' trees received foliar spray of urea (22 or 43 g N $tree^{-1}yr^{-1}$) or soil application of urea (86 g N $tree^{-1}yr^{-1}$). 56% of N was applied in spring, 11% in summer and 33% in fall. There were seven trees per N treatment and two trees per N treatment received $^{15}N$-labeled urea in spring and summer to determine N recovery. There were no differences between the treatments for fruit yield and its quality. Nitrogen content of spring flush leaf blades up to early September was greater for trees received foliar spray comparing with soil application but was not greatly affected by any treatment after mid-November. The recovery of fertilizer N in various parts of trees receiving foliar spray of 22 g N $tree^{-1}yr^{-1}$ was greatest, followed by receiving foliar spray of 43 g N and soil application of 86 g N. The recovery of fertilizer N in tree was 29.2 and 17.7% for foliar spray of 22 and 43 g N $tree^{-1}yr^{-1}$, respectively and 8.0% for soil application of 86 g N $tree^{-1}yr^{-1}$. The recovery of fertilizer N in the upper 40 cm of soil was 50.3, 45.6, and 51.8% for foliar spray of 22 and 43 g N $tree^{-1}yr^{-1}$, and soil application of 86 g N $tree^{-1}yr^{-1}$ respectively. The total (tree, fallen leaves, winter weeds, and soil) recovery of fertilizer N was 81.8, 65.1, and 60.6% for foliar spray of 22 and 43 g N $tree^{-1}yr^{-1}$, and soil application of 86 g N $tree^{-1}yr^{-1}$, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.7
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• pp.820-825
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• 2007

Earthworm casting was the natural fertilizer that contained high concentrations of nutrients such as nitrogen, phosphate and potassium and of over $10^8$ CFU/ml of microorganisms. Greater than 80% of feed was excreted through the fermentation by the intestinal enzyme, after worm had eaten feeds such as fallen leaves and rotten roots under the ground. Also, the soil structure of casting was known to be very efficient in the aspects of the porosity, the water permeability, and deodorizing activities. In this research, the biofilter packed with a biomedia made of casting and waste polyurethane foam, a binder, which helped to improve the durability and perpetuity of casting, was investigated to degrade malodorous hydrogen sulfide gas. The biomedia had no need of extra supply of nutrients and of microbial inoculations. On the beginning of the operations, it showed 100% removal of hydrogen sulfide gas without lag phase. At SV of 50 $h^{-1}$, hydrogen sulfide gas from the outlet of the biofilter was not detected, when inlet concentration increased to 450 ppmv. After that, removal efficiency decreased as increasing inlet hydrogen sulfide concentration. Hydrogen sulfide removal was maintained at almost 93% until inlet concentration was increased up to 950 ppmv, at which the elimination capacity of $H_2S$ was 61.2 g $S{\cdot}m^{-3}{\cdot}h^{-1}$. Maximum elimination capacity guaranteing 90% removal was 61.2, 65.9, 84.7, 89.4 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV ranging from 50 $h^{-1}$ to 300 $h^{-1}$, but was 59.3 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ at SV of 400 $h^{-1}$. The results calculated from Michaelis-Menten equation revealed that $V_m$ increased from 66.04, 88.96, 117.35, 224.15, to 227.54 g $S{\cdot}m^{-3}{\cdot}h^{-1}$ with increasing space velocity in the range of 50 $h^{-1}$ to 400 $h^{-1}$. However, saturation constant$(K_s)$ decreased from 79.97 ppmv to 64.95 and 65.37 ppmv, and then increased to 127.72 and 157.43 ppmv.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.21-27
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• 1998

This experiment was conducted to increase aromatics in roots of Condonopsis lanceolata by applications of organic matters. Fresh root wt. was increased by conifer/moss application to 79.1g per plant. Crude protein content was also higher at rice straw application than native soil application and crude saponin content was increased by conifer/moss application, but contents of crude fat, fiber and ash were not different in all treatments. Although contents of K, Ca, and Mg were increased by rice straw application, Fe, Mn, Zn, Na and Cu were not significantly different in all treatments, The highest free amino acid was arginine, it was increased by the application of fallen leaves and the highest yield (0,008%) of essential oils was obtained by conifer/moss application. As a result, to produce C. lanceolata plant showing higher quality and aromatic essential oils, it was considered that the most effective organic matter showing high yield and higher aromatic constituents was conifer/moss application of over 3M/T per 10a.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.255-265
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• 1999

This study deals with forest soil characteristics and their effects on the trafficability of logging vehicles. The study area is the national experimental forest located in Kwangnung. This site has 20m length and is equally divided by 5 surveying ranges with 4m width, on which a tractor(FIATAGRI) attached with logging boogie can drive in 4 driving types, namely 1time-return unload, 1time-return with load of 780-790kg weight of 3 logs, 5 and 10times-return with same load. After one driving type on all surveying ranges, the soil hardness is surveyed 5 times with 3 several type tools, SHM-1 type, lang penetrometer(L-PNTM), and clegg impact soil tester(CIST). A disturbed degree of cover vegetation and sliding conditions of vehicle are also observed. As results, the soil type of the test site was SC by USCS and dry brown forest soil. The cover vegetation is gotten trambled under driving after 3-5 times-return, shrubs leaves are fully fallen and their bark are peeled, and after 10 times-return the cover vegetations were nearly disappeared. The test vehicle has neither slided nor was overthrown. The wheel tracks in the 1-3 ranges, of which unit weight(gd, gt) is high and soil moisture content(MC) is low, were only 1-2cm deep, but those in the 4-5 ranges, of which the gd, gt is low and the MC is high, were 5-7cm deep. In the soil hardness test, which was established in 5 test ranges by types of driving, the more driving times, the higher the hardness. The soil hardness surveyed by L-PNTM has changed slowly and that surveyed by SHM-1 type has risen sharply. In the ranges with higher specific gravity(Gs), higher unit weight, lower MC and higher liquid limit(LL) and plasticity index(PI) was the soil hardness high and the trafficability was good. In the ranges with opposite conditions, also in the ranges of the lower soil hardness, the trafficability must be not good, because the wheel track may be deep. The results from CIST attached with 4kg hammer was not better than expected. So it is recommended to use CIST with 2.5kg or 0.5kg hammer.