• Korean Journal of Ecology and Environment
• /
• v.54 no.2
• /
• pp.120-124
• /
• 2021

In order to understand the vegetative role of Glycine soja, we studied the basic physiological characteristics between Glycine soja and Glycine max. For this study, the light intensity (μmol m^-2 s^-1) on leaf surface, leaf temperature (℃), transpiration rate (mmol m^-2 s^-1), photosynthetic rate (μmol m^-2 s^-1), substomatal CO₂ partial pressure (vpm) of Glycine soja and Glycine max were measured, and the quantum yield, photosynthesis rate per substomatal CO₂ partial pressure were calculated. In the results of simple regression analysis, the increasing quantum yield decreases leaf temperature both of Glycine soja and Glycine max and the increasing leaf temperature decreases transpiration rate in case of Glycine soja. However, in case of Glycine max, the increasing leaf temperature decreases substomatal CO₂ partial pressure, photosynthetic rate, and photosynthetic rate per substomatal CO₂ partial pressure as well as transpiration rate. Also, increasing transpiration rate increases substomatal CO₂ partial pressure while decreases photosynthetic rate per substomatal CO₂ partial pressure. Thus, Glycine soja is relatively more easily adaptable to severe environments with low soil nutrients and high light levels. Compared to Glycine max susceptible to water loss due to a water-poor terrestrial habitat, the physiological traits of Glycine soja has a high average transpiration rate and are less susceptible to water loss will act as a factor that limits the habitat according to soil moisture.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.2132-2137
• /
• 2009

갈대(Phragmites communis Trin.)란 염분이 있는 곳에서 자라는 염생식물로서 우리나라 전역에 분포하고 있다. 지난 50년 동안 우리나라의 여러 습지에 걸쳐서 갈대는 우점종으로 자라왔고, 육지와 수중서식지에서 갈대의 확산범위는 증가하고 있다. 갈대의 확산은 다른 습지 식물의 서식지를 파괴하고, 갈대가 번식하면 동 식물들의 번식 자체가 어려울 뿐 아니라 갈대숲에 포식자가 늘어나 살아가기 어려운 환경으로 변하기때문에 갈대를 체계적으로 관리할 수 있는 방안이 마련되어야 한다. 본 연구는 우점종이 다른 두 습지에서 갈대군집의 성장률을 관찰하고, 토양의 화학적 분석과 식물의 생리적 분석을 통해 갈대군집 성장에 미치는 영양염류의 영향을 규명하였다. 연구 대상지는 한강하구에 위치한 장항습지와 성동습지로서 동일하게 갈대가 분포하며, 장항습지에는 줄 군락이 성동습지에는 새섬매자기 군락이 우점하고 있다. 분석 항목은 이화학적 항목을 비롯하여 용존유기탄소(DOC, dissolved organic carbon), 체외미생물효소활성도(Extracellular enzyme activities), 암모니아성 질소($NH_4^+$), 질산성 질소($NO_3^-$)을 분석하였다. 실험결과, 두 습지 갈대의 성장은 7월부터 9월에 증가하였고 성동습지의 토양성분이 점토질로 형성되어 높은 수분함량과 유기물함량을 유지하고 있기 때문에 갈대의 밀도가 높고 성장률이 활발한 것으로 나타났다. 또한 미생물활성과 환경인자간 양의 상관관계를 보아 환경인자들이 미생물 활성을 자극하고 미생물들은 식물의 성장을 촉진하여 영향을 주며, 반면 식물 뿌리는 enzyme을 생성하는 미생물에게 C 삼출물을 공급해 enzyme 활성에 영향을 미칠 것으로 사료된다.

• Microbiology and Biotechnology Letters
• /
• v.38 no.3
• /
• pp.302-307
• /
• 2010

Nitrogen is an element need to grow plants growth. Plants take up nitrogen in the form of nitrate or ammonium. Most of plants absorb nitrogen source as fertilizers. But from 50 to 70% of fertilizers applied were washed away. This study was conducted to isolate free-living nitrogen fixing bacteria from reed and to examine its beneficial traits for developing sustainable biofertilizers. Enriched consortium obtained from a reed in Ansan was developed for the fixing of nitrogen. Nitrogen fixing bacteria isolated from an enriched culture in Congo Red Medium was analyzed by 16s rDNA sequencing. AKC-10 was isolated and shown to have excellent nitrogen fixing ability. The optimum conditions of nitrogen fixing ability were $25^{\circ}C$ ($237.50{\pm}39.65\;nmole{\cdot}mg-protein^{-1}{\cdot}h^{-1}$ and pH 7 ($168.335{\pm}12.84$ nmole/hr mg-protein). It was identified as Microbacterium hominis [(AKC-10 (similarity : 99%)]. This strain was had to IAA (indole-3-acetic acid) productivity and ACC(1-aminocyclopropane-1-carboxylic acid) deaminase activity. Therefore, Microbacterium hominis AKC-10 stimulated plant development in the soil, enhancing the efficiency of remediation.

• The Korean Journal of Ecology
• /
• v.21 no.1
• /
• pp.47-63
• /
• 1998

In order to compare species-specific calcium metabolism, we collected 127 species belonging to 40 different families grown on various habitats including saline, limestone, wetland during the 1996 vegetation period, and analyzed their inorganic ion contents. Plants investigated were divided into 5 groups according to their physiological properties: 1) Chenopodiaceae, Aizoaceae, Caryophyllaceae, Portulacaceae and Phytolaccaceae of Centrospermales and Polygonaceae (Polygonales had a little water-soluble $Ca^{2+}$ but contained high contents of insoluble $Ca^{2+}$ particularly as Ca-oxalate (Chenopodiaceae type), 2) Some plant species such as Rosaceae produced oxalate in amounts insufficient to precipitate all incoming $Ca^{2+}$ and thus contained a surplus of dissolved $Ca^{2+}$ (Rosaceae type), 3) The contents of water-soluble $Ca^{2+}$ in plant species of Crassulaceae. Plantaginaceae, Asclepiadaceae, and Zygophyllaceae were equal to or greater than those of K ($K/Ca{\leq}1$; Crassulaceae type), and 4) K/Ca ratios of Compositae were significantly fluctuated depending on species and soil $Ca^{2+}$ level of their habitats (Compositae type). 5) Certain monocots (Gramineae, Cyperaceae, Juncaceae), in contrast to the dicotyledonous plant families mentioned above, showed a very distinct type of calcium metabolism, that is, the K/Ca ratios of 8~10 were maintained indifferently in the species and their habitat types (Graminae type). These results plants within the same taxon have similar physiological aspects as weel as morphological attributes. To understand calcium metabolism of certain plant species, therefore, it is desirable to approach on the basis of physiological concept (calciotroph or calciophobe) rather than the ecological one (calcicole or calcifuge).

• Environmental Engineering Research
• /
• v.19 no.3
• /
• pp.185-195
• /
• 2014

Despite the enormous technical and economic efforts to improve environmental conditions, currently about 40% of the global population (or 2 billion people) are still lack access to safe water supply and adequate sanitation facilities. Pollution problems and transmission of water- related diseases will continue to proliferate. The rapid population growth and industrialization will lead to a reduction of arable land, thus exacerbating the food shortage problems and threatening environmental sustainability. Natural systems in this context are a transdisciplinary approach which employs the activities of microbes, soil and/or plants in waste stabilisation and resource recovery without the aid of mechanical or energy-intensive equipments. Examples of these natural systems are: waste stabilisation ponds, aquatic weed ponds, constructed wetlands and land treatment processes. Although they require relatively large land areas, the natural systems could achieve a high degree of waste stabilisation and at the same time, yield potentials for waste recycling through the production of algal protein, fish, crops, and plant biomass. Because of the complex interactions occurring in the natural systems, the existing design procedures are based mainly on empirical or field experience approaches. An integrated kinetic model encompassing the activities of both suspended and biofilm bacteria and some important engineering parameters has been developed which could predict the organic matter degradation in the natural systems satisfactorily.

• Journal of Biosystems Engineering
• /
• v.9 no.2
• /
• pp.8-18
• /
• 1984

To investigate the most important factors affecting the mobility of power tiller and to find the method which can be used for predicting the mobility of power tiller in soft paddy field, a series of field experiment was performed with two models of power tiller (8ps and 6ps diesel). From the results obtained throughout field experiment, the following conclusions were derived. 1. The wheel sinkage of power tiller during both traveling and field operations, which mainly influence the mobility, could be predicted from both plate ($50{\times}100mm$) sinkage and soil cone index (30-degree cone with 2 and $6cm^2$ base area). 2. Prediction of wheel sinkage from the rectangular plate sinkage was found to be more suitable compared with the cone index. 3. The upper limit of rectangular plate sinkage was found as 15 centimeter for operation of power tiller in muddy field which is equivalent of $1kg/cm^2$ of $2cm^2$ cone index value.

• Korean Journal of Remote Sensing
• /
• v.23 no.3
• /
• pp.181-188
• /
• 2007

The objective of this research was to investigate the optimal land cover classification algorithm for the monitoring of North Korea with MODIS multi-temporal data based on monthly phenological characteristics. Three frequently used land cover classification algorithms, ISODATA1), SMA2), and SOM3) were employed for this study; the land cover categories were forest, grass, agricultural, wetland, barren, built-up, and water body. The outcomes of the study can be summarized as follows. First, the overall classification accuracy of ISODATA, SMA, and SOM was 69.03%, 64.28%, and 73.57%, respectively. Second, ISODATA and SMA resulted in a higher classification accuracy of forest and agricultural categories, but SOM performed better for the built-up area, bare soil, grassland, and water. A possible explanation for this difference would be related to the difference of sensitivity against the vegetation activity. This would be related to the capability of SOM to express all of their values without any loss of data by maintaining the topology between pixels of primitive data after classification, while ISODATA and SMA retain limited amount of data after normalization process. Third, we can conclude that SOM is the best algorithm for monitoring the land cover change of North Korea.

• Journal of Species Research
• /
• v.10 no.3
• /
• pp.217-226
• /
• 2021

During a project aiming to comprehensively investigate indigenous prokaryotic species in Korea, a total of 20 bacterial strains phylogenetically belonging to the the class Bacilli of the phylum Firmicutes were isolated from various environmental sources such as soil, air, tidal flat, sea water, grain, wetland, breast milk and healthy human urine. Phylogenetic analysis based on 16S rRNA gene sequences revealed that 20 bacterial strains showed the high sequence similarities (≥98.7%) to the closest type strains and formed robust phylogenetic clades with closely related species of validly published names in the class Bacilli of the phylum Firmicutes. In the present study, we report 20 species of 13 genera of seven families of two orders of one class in the phylum Firmicutes, which have not been previously reported in Korea. Morphological, biochemical, and physiological characteristics, isolation sources, and NIBR deposit numbers of these unrecorded bacterial species are described in the species descriptions.

• Journal of Species Research
• /
• v.10 no.3
• /
• pp.191-200
• /
• 2021

To study the biodiversity of bacterial species, here we report indigenous prokaryotic species of Korea. A total of 23 bacterial strains affiliated to the class Alphaproteobacteria were isolated from various environmental sources including seaweeds, seawater, fresh water, wetland/marsh, tidal sediment, plant roots, sewage and soil. Considering higher than 98.8% 16S rRNA gene sequence similarities and formation of a well-defined phylogenetic clade with named species, it was confirmed that each strain belonged to the predefined bacterial species of the class Alphaproteobacteria. There is no official report of these 23 species in Korea; 20 species of 16 genera (Mameliella, Yangia, Paracoccus, Ruegeria, Loktanella, Phaeobacter, Dinoroseobacter, Tropicimonas, Lutimaribacter, Litoreibacter, Sulfitobacter, Roseivivax, Labrenzia, Hyphomonas, Maricaulis, Thalassospira) in the order Rhodobacterales and 3 species of a single genus (Brevundimonas) in the order Caulobacterales. Gram-staining, cell morphology, basic biochemical characteristics, isolation sources, optimum temperature, growth media, and strain IDs are detailed in the species description as well as Table 1.

• Journal of Species Research
• /
• v.12 no.3
• /
• pp.212-223
• /
• 2023

A total of 30 bacterial strains were identified in the classes Betaproteobacteria and Gammaproteobacteria in the study of prokaryotic species in Korea. These strains were isolated from a variety of environmental sources, including soil, tidal flat, mud, wetland, pine cone, seaweed, sea sediment, and brackish water. Phylogenetic analysis showed that isolates were identified based on high 16S rRNA gene sequence similarities (≥98.7%) with the predefined bacterial type species. In this study, we present data on previously unreported species from Korea, including 10 species from three families of one order in the class Betaproteobacteria and 20 species from 12 families of nine order in the class Gammaproteobacteria. Morphological, biochemical characteristics, isolation sources, and NIBR deposit numbers are provided in the description sections.