• Title/Summary/Keyword: Ha-So

Search Result 3,552, Processing Time 0.035 seconds

Forest Stand Structure, Site Characteristics and Carbon Budget of the Kwangneung Natural Forest in Korea (광릉 활엽수천연림의 산림식생구조, 입지환경 및 탄소저장량)

  • Jong-Hwan Lim;Joon Hwan Shin;Guang Ze Jin;Jung Hwa Chun;Jeong Soo Oh
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • v.5 no.2
    • /
    • pp.101-109
    • /
    • 2003

  • The study area, Kwangneung Experiment Forest (KEF) is located on the west-central portion of Korean peninsula and belongs to a cool-temperate broadleaved forest Bone. At the old-growth deciduous forest near Soribong-peak (533.1 m) in KEF, we have established a 1 ha permanent plot ($100m{\times}100m$) and a flux tower, and the site was registered as a KLTER(Korean long-term ecological research network) and DK site of KoFlux. In this site, we made a stemmap of trees and analyzed forest stand structure and physical and chemical soil characteristics, and estimated carbon budgets by forest components (tree biomass, soils, litter and so on). Dominant tree species were Quercus serrata and Carpinus laxiflora, and accompanied by Q. aliena, Carpinus cordata, and so on. As a result of a field survey of the plot, density of the trees larger than 2 cm in DBH was 1,473 trees per ha, total biomass 261.2 tons/ha, and basal area $28.0m^2$/ha. Parent rock type is granite gneiss. Soil type is brown forest soil (alfisols in USDA system), and the depth is from 38 to 66 cm. Soil texture is loam or sandy loam, and its pH was f개m 4.2 to 5.0 in the surface layer, and from 4.8 to 5.2 in the subsurface layer. Seasonal changes in LAI were measured by hemispherical photography at the 1.2 m height, and the maximum was 3.65. And the spatial distributions of volumetric soil moisture contents and LAIs of the plot were measured. The carbon pool in living tree biomass including below ground biomass was 136 tons C/ha, and 5.6 tons C/ha is stored in the litter layer, and about 92.0 tons C/ha in the soil to the 30 cm in depth. Totally more than about 233.6 tons C/ha was stored in DK site. These ground survey and monitoring data will give some important parameters and validation data for the forest dynamics models or biogeochemical dynamics models to predict or interpolate spatially the changes in forest ecosystem structure and function.

  • PDF KSCI

The Development of Buried Type Reference Electrode Using Porous Ceramic(${\alpha}-Al_{2}O_{3}$) (다공성 세라믹(${\alpha}-Al_{2}O_{3}$)를 이용한 지중 매설형 기준전극)

  • Bae, Jeong-Hyo;Ha, Yoon-Cheol;Ha, Tae-Hyun;Lee, Hyun-Goo;Kim, Dae-Kyeong
    • Proceedings of the KIEE Conference
    • /
    • 2005.11a
    • /
    • pp.145-147
    • /
    • 2005

  • In present, most of metallic structures(gas pipeline, oil pipeline, water pipeline, etc) are running parallel with subway and power line in seoul. Moreover subway system and power line make a stray current due to electrical corrosion on metallic structures. The owner of metallic structures has a burden of responsibility for the protection of corrosion and the prevention against big accident such as gas explosion or soil pollution and so on. So, they have to measure and analyze the data about P/S(Pipe to Soil) potential due to stray current of subway system. So, we have developed the Real-time Wireless Remote Monitoring System for Stray Current of Subway System. In this system, the permanent buried type reference electrode is necessary. In this paper, results of development of buried type reference electrode using porous ceramic$({\alpha}-Al_{2}O_{3})$ are presented.

  • PDF

Comparison in Structural Characteristics and Phenanthrene Sorption of Molecular Size-Fractionated Humic Acids (분자량 크기별 토양 휴믹산(HA)의 구조적 특성 및 페난트렌 흡착 반응특성 비교)

  • Lee, Doo-Hee;Kim, So-Hui;Shin, Hyun-Sang
    • Journal of Soil and Groundwater Environment
    • /
    • v.20 no.7
    • /
    • pp.70-79
    • /
    • 2015

  • A sample of soil humic acid (HA) was divided by ultrafiltration (UF) into five fractions of different molecular size (UF1: > 300, UF2: 100~300, UF3: 30~100, UF4: 10~30, UF5: 1~10 kilodaltons). Apparent average molecular weight (Mw) of the HA fractions were measured using high performance size exclusion chromatography (HPSEC), and the chemical and structural properties of the five HA fractions were characterized by elemental compositions (H/C, O/C and w ((2O + 3NH)/ C)) and ultraviolet-visible absorption ratios (SUVA, A4/6). The organic carbon normalized-sorption coefficients (Koc) for the binding of phenanthrene to the HA fractions were determined by fluorescence quenching and relationship between the sorption coefficients and structural characteristics of the HA fractions were investigated. The elemental analysis and UV-vis spectral data indicated that the HA fractions with higher molecular weights have grater aliphatic character and lower contents of oxygen, while the HA fractions with lower molecular size have greater aromatic character and molecular polarity that correspond to greater SUVA and internal oxidation values (w). The log Koc values (L/kg C) were gradual increased from 4.45 for UF5 to 4.87 for UF1. The correlation study between the structural descriptors of the HA fractions and log Koc values of phenanthrene show that the magnitude of Koc values positively correlated with $M_w$ and H/C, while negatively correlated with the independent descriptors of the O/C, w, SUVA and A4/6.

  • https://doi.org/10.7857/JSGE.2015.20.7.070 인용 PDF KSCI KPUBS HTML