• Title/Summary/Keyword: LITTER COMPONENT

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Allelopathic Potential of Adhtoda vasica NEES (Adhatoda visica NEES의 알레로페티 효과)

  • Sajjida, Ayaz;Hussain, Farrukh;Ilahi, Ihsan;Kil, Bong-Seop
    • Journal of Plant Biology
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    • v.32 no.2
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    • pp.109-119
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    • 1989
  • Adhatoda vasica Nees is a shrubby component of tropical and subtropical vegetation in Pakistan. t harbours relatively few unhealthy associated species in and around its thickets. Aqueous extracts, rain leachates, litter from shoots and soil underneath it invariably reduced germination, early growth, biomass, moisture and chlorophyll contents of Pennisetum americanum, Setaria italica, Zea mays, Brassica campestris and Triticum vulgare in different laboratory expreiments. chromatographic analysis revealed the presence of caffeic, ferulic, vanillic, p-coumaric, p-OH-benzoic, and tannic acids in aqueous extracts. The phytotoxicity was related to the test species used, part assayed and parameter measured. It is suggested that the preclusion of the associated species and the dominance of A. vasica is primarily due to allelopathy. Negative grazing also provides better chances for its establishment.

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Nutrient Intake and Utilization by Range Managed Sheep in Critical Physiological Stages Maintained on Grazing with Concentrate Supplementation in a Hot Semi-Arid Environment

  • Karim, S.A.;Santra, A.;Sharma, V.
    • Asian-Australasian Journal of Animal Sciences
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    • v.13 no.9
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    • pp.1228-1234
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    • 2000
  • The reported study was conducted on range managed Malpura ewes that were non-breeding empty, were at an advanced stage of pregnancy, and were in early lactation, under a protocol of free grazing with concentrate supplementation at 1.00, 1.25 and 1.50% of their body weight to assess their plane of nutrition and nutrient intake. The biomass yield of pasture plots was 1689, 1820 and 2912 kg/ha in pregnancy, lactation and empty phases, respectively. In addition to natural shrubs and forbs, Cenchrus ciliaris (36.4%) and dead litter (31.6%) were the major component of pasture vegetation during pregnancy. The dead litter disappeared during the lactation and empty phase with a concomitant increase in distribution of Cenchrus ciliaris to 73.0 and 87.2% respectively. The daily dry matter consumption from supplemental concentrate and free grazing was 70.1, 57.3 and 63.5 g/kg $W^{0.75}/d$ with concentrate to roughage ratio of 40:60, 47:53 and 33:67 in pregnancy, lactation and empty phases respectively. Digestibility of DM and OM were similar in the three phases while CP digestibility was higher (p<0.0l) during lactation than other two phases. Digestibility of NDF, ADF and cellulose were higher (p<0.0l) in empty than pregnancy and lactation, while hemicellulose digestibility was similar in lactation and empty and lower in pregnancy phase. The ewes in ~hases of pregnancy, lactation and empty consumed 7.1, 7.7 and 6.1 g DCP and 197.2, 214.6 and 232.5 kcal DE/kg $W^{0.75}/d$ respectively. It is concluded that ewes maintained on semi-arid Cenchrus dominated pasture with concentrate supplementation during pregnancy, lactation and empty phases consumed 45.2, 45.1 and 35.2 g DCP/Mcal ME respectively.

Effects of controlled environmental changes on the mineralization of soil organic matter

  • Choi, In-Young;Nguyen, Hang Vo-Minh;Choi, Jung Hyun
    • Environmental Engineering Research
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    • v.22 no.4
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    • pp.347-355
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    • 2017
  • This study investigated how the combined changes in environmental conditions and nitrogen (N) deposition influence the mineralization processes and carbon (C) dynamics of wetland soil. For this objective, we conducted a growth chamber experiment to examine the effects of combined changes in environmental conditions and N deposition on the anaerobic decomposition of organic carbon and the emission of greenhouse gases from wetland soil. A chamber with elevated $CO_2$ and temperature showed almost twice the reduction of total decomposition rate compared to the chamber with ambient atmospheric conditions. In addition, $CO_2$ fluxes decreased during the incubation under the conditions of ambient $CO_2$ and temperature. The decrease in anaerobic microbial metabolism resulted from the presence of vegetation, which influences the litter quality of soils. This can be supported by the increase in C/N ratio over the experimental duration. Principle component analysis results demonstrated the opposite locations of loadings for the cases at the initial time and after three months of incubation, which indicates a reduction in the decomposition rate and an increasing C/N ratio during the incubation. From the distribution between the decomposition rate and gas fluxes, we concluded that anaerobic decomposition rates do not have a significantly positive relationship with the fluxes of greenhouse gas emissions from the soil.

Effect of Splenectomy on the Blood Component and Reproductive Performance accordingto Gestation in Rats (비장적출이 임신 rat의 혈액성분 및 번식력에 미치는 영향)

  • 정원철;오석두;성환후;정진관;윤창현;이병오
    • Korean Journal of Animal Reproduction
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    • v.18 no.3
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    • pp.167-174
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    • 1994
  • This experiment was undertaken to investigate the effect of splenectomy on the hematology and maintenance of pregnant rats. Those animals that had shown regular 4 or 5 day estrous cycles for more than two cycles were used. The day after mating ws designated Day 0 of pregnancy. Spleen was removed from Day 0(early), 6(middle) and 13(late) of pregnant rat, respectively. Blood was collected on Day 1, 7, 14 and 21 of the pregnancy. 1. The total serum protein was increased significantly (P<0.05) to the progress of pregnancy in control rat. All rats that splenectomized groups were decreased significantly(P<0.05) at Day 21 of pregnancy than control rats. 2. Albumin was not significantly changed. 3. Globulin was decreased significantly(P<0.05) between contol and middle treatment at Day 7, 14 of pregnancy. 4. Glucose was increased for the due to the pregress of pregnancy. It was no significance differences among the each groups. 5. Rate of abortion was increased in groups of early and middle of splenectomy compared with control. 6. Period of pregnancy was delayed in middle and late splenectomized gruops companed with control. 7. Litter size was lowed significantly (P<0.05) in early and middle splenectomized groups compared with control.

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Estimation of Genetic Parameters for Four Reproduction Component Traits in Two Chinese Indigenous Pig Breeds

  • Zhu, M.J.;Ding, J.T.;Liu, B.;Yu, M.;Fan, B.;Li, C.C.;Zhao, S.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.8
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    • pp.1109-1115
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    • 2008
  • The reproduction component traits are important components of sow efficiency. The objective of this study was to evaluate the phenotypic and genetic parameters of four reproduction component traits (age at puberty (AP), preweaning number dead (PND), weaning to service interval (WSI), and intra-individual SD in litter size (IISDLS)) of sows in two Chinese indigenous pig breeds. Available reproductive records including 22,591 piglets born from 2,054 litters by 574 Jiangquhai sows and 464 Meishan sows were used in this investigation. A set of mixed models and restricted maximum likelihood methodology were used for the multiple trait analyses of these traits. The results showed that the estimates of heritabilities (${\pm}$standard error) for AP, PND, WSI and IISDLS were $0.40{\pm}0.05$, $0.06{\pm}0.03$, $0.20{\pm}0.02$ and 0.09{\pm}0.03 in Jiangquhai sows, and $0.35{\pm}0.06$, $0.05{\pm}0.03$, $0.18{\pm}0.03$ and $0.10{\pm}0.04$ in Meishan sows, respectively. There was moderate genetic correlation between AP and WSI, while there were low genetic correlations between the other pairwise traits. The genetic correlations were positive for most of the pairwise traits, except for the one between AP and IISDLS. The results indicated that all traits except for AP were difficult to make genetic improvement by traditional selection methods due to low heritabilities and the favorable improvement of AP might result in unfavorable changes of IISDLS due to the trend of genetic antagonism.

Estimation of Aboveground Biomass and Belowground Nutrient Contents for a Phyllostachys pubescens stand (맹종죽(孟宗竹) (Phyllostachys pubescens) 임분(林分) 내(內) 지상부(地上部) 생체량(生體量) 및 지하부(地下部) 양분(養分) 함량(含量) 추정(推定))

  • Hwang, Jaehong;Chung, Young-Gyo;Lee, Sang-Tae;Kim, Byung-Bu;Shin, Hyun-Cheol;Lee, Kyung-Jae;Park, Kyu-Jong
    • Journal of Korean Society of Forest Science
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    • v.94 no.3 s.160
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    • pp.161-167
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    • 2005
  • Above and belowground biomass for Phyllostachys pubescens was determined in Jinju, Gyeongsangnam-do. Regression analyses of dry weights of culms, foliages, and twigs versus diameter at breast height were used to calculate regression equations of the form of log Y = a + blogX. Total aboveground biomass for Phyllostachys pubescens was 69.7 ton/ha and rhizomes and roots biomass were 13.7 ton/ha and 7.5 ton/ha, respectively. Culms account for about 60% of total aboveground biomass. The aboveground biomass of each component was decreased in the order of culms>foliages>twigs. As diameter at breast height grew thicker, the proportion of culms to total aboveground biomass increased. The proportion of dry weight of culms to green weight gradually increased with height in a bamboo tree and ages. Nutrients (kg/ha) of litter layer were distributed as follows: N(45.1), Ca(17.3), K(6.1), Mg(3.6), P(3.5) and Na(0.7). Nitrogen and K were given much weight in total nutrients of rhizomes and roots. These results will be useful in measuring carbon stock and drawing up management plan to increase it for Phyllostachys pubescens stand.

Application of Landsat ETM Image to Estimate the Distribution of Soil Types and Erosional Pattern in the Wildfire Area of Gangneung, Gangweon Province, Korea (강원도 강릉시 산불지역에서의 토양유형의 분포와 침식양상파악을 위한 Landsat ETM 영상의 활용)

  • Yang, Dong-Yoon;Kim, Ju-Yong;Chung, Gong-Soo;Lee, Jin-Young
    • Journal of the Korean earth science society
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    • v.25 no.8
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    • pp.764-773
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    • 2004
  • The soil in wildfire area Sacheon-myeon, Gangneung, Gangweon Province, Korea, were investigated to clarify pattern of the soils. The soils were classified into 5 types on the basis of vegetation, types of organic matter. thickness of soil horizons, and completeness of soil profile. Each type showed different erosion pattern and Landsat ETM image. Coverage of plant leaves, litter, root, ash and other organic matter was an important component that affected soil color and reflectance of Landsat image (digital number). Although the NDVI (Normalized Distribution Vegetation Index) method in the wildfire area did not show much difference in soil types, the applied supervised classification method showed characteristic pattern of Landsat ETM image of soil types. This study showed that the applied supervised Landsat TM image classification in wildfire area is an effective way to estimate the distribution of erosion pattern of soil in wildfire area.

Annual Variations of Litterfall Production in a Broadleaved Deciduous Forest at the Mt. Keumsan LTER Site (금산 장기생태연구 조사지 낙엽활엽수림 낙엽낙지량의 연변동)

  • Kim, Choonsig;Lim, Jong Hwan;Lee, Im Kyun;Park, Byung Bae;Chun, Jung Hwa
    • Journal of Korean Society of Forest Science
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    • v.102 no.2
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    • pp.210-215
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    • 2013
  • Litterfall production represents a major contribution of carbon and nutrient cycling in forest ecosystems. This study was carried out to determine the litterfall production in a broadleaved deciduous forest at the Mt. Keumsan Long Term Ecological Research (LTER) site, Southern Korea. Littefall was collected monthly or bimonthly from the site for 7 years from 2004 to2010. Leaf and reproductive (catkins) litters showed a seasonal variation, but litters of needle, branch, and barks were not changed across the seasons. Annual leaf litter of Quercus serrata and Carpinus laxiflora were significantly different (p<0.05) but that of C. cordata, Chamaecyparis obtusa, and Pinus thunbergii was not significantly changed for 7 years (p>0.05). Annual average litterfall production was 5,223 kg/ha, but annual variations were very large with minimum of 4,110 kg/ha/yr in 2004 and maximum of 6,002 kg/ha/yr in 2007. Total litterfall comprised of 2,323 kg/ha/yr in Q. serrata, 442 kg/ha/yr in C. laxiflora, 157 kg/ha/yr in C. cordata, 131 kg/ha/yr in Acer pseudosieboldianum, 390 kg/ha/yr in other deciduous tree species, 74 kg/ha/yr in P. thunbergii, 37 kg/ha/yr in C. obtusa, 672 kg/ha/yr in branches, 515 kg/ha/yr in miscellaneous, 448 kg/ha/yr in reproductive parts, and 54 kg/ha/yr in barks. respectively. The results indicate that litterfall production of the Mt. Keumsan LTER site was yearly fructurated with the positive linear relationship between leaf or total litterfall and annual mean temperature if no disturbance such as a typoon, and was lower than that of other Korean LTER sites.

Ecological Functions and Losses of Traditional Korean Village Groves

  • Lee, D.-W.;Park, C.-R.
    • The Korean Journal of Quaternary Research
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    • v.18 no.2 s.23
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    • pp.65-66
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    • 2004
  • There have been groves, in many cases, along with hedgerows and remnant forests around a traditional Korean village. A village grove is very closely connected to the life of residents. Sometimes it was a holy place where important village festivals were held, and became a resting place for farmers, especially in sunny summer. As a matter of fact, it is noted that traditional Korean village groves had been fostered for many purpose as religion, Confucianism, scenery, sanitation, traffic guard, public security, agriculture, hunting, and military and public uses were included in Chosun Govemor General(1938). Village groves were usually located at the outlet of watershed inside which a village was built. In addition, village groves used to be established along part of mountain ranges, streams and streets. A unique type of village grove, called bibosoop was fostered especially where the outlet of watershed was largely opened. In other cases, it was placed where a part of mountain range was relatively low, or where village residents were likely to see ugly objects such as a huge cliff, stony upland with an unvegetated area and the like(Kim and Jang 1994). In a sense, a sheltebelt is a sort of bibosoop as it is a landscape element to complement places that are exposed to strong winds. However, it is comparable to other typical bibosoop that is situated at a topographically very specific zone of watershed. In this paper, we will address potential functions of Korean village groves from a perspective of modern landscape ecology and show current status of some remnants, based on preliminary surveys. A village grove functions as barrier or filter of objects such as water, nutrients, and other elements and habitat of wildlife (park et al. 2003, Lee 2004). The village grove slows down the flow of water and air, maintains soil moisture an hinders soil erosion, enabling cultivation of crops and bringing up creatures nearby. It contributes to enhancing biodiversity. Birds rest on shrubby and woody trees of the element. Presumably, other organisms may also inhabit the village groves and take advantage of it when those move from a forest patch to others. Emerging insects acclimate themselves in the shade of the green space before they fly to sunny air. Besides the village grove acts as a component of agroforestry system as leaf litter is shed from a grove to an asjacent agricultural area, and transformed into green manure(Lee 2004). By the way, many of the landscape elements were destroyed or declined in Koea during the past several decades. The losses have been parallel or linked to environmental degradation. Unfortunately, we have a little reliable data as for how many groves have disappeared in Korea until now. There has been no complete census on the village groves in Korea, and the viewpoints of survey were to a degree different depending on surveyors. So, it is difficult to analyze the temporal and spatial change of village groves. Currently, national inventory data of Korean village groves are available in three reports. We reviewed the locations of village groves and arranged those according to the present administrative units, DONG. With the limited data, we found that at least 484 of village groves were recorded in South Korea. Among all provinces, village groves were most in Gyeongsanbuk-Do Province and least in Chungcheongbuk-Do Province(Table 1). This is a preliminary report prepared while some quantitative data regarding functions and lossers of the village groves are being collected. More detailed data will be introduced in the near future.

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Performance Improvement of the battening Effect of the new Asymmetric Turbo Codes (새로운 비대칭 구조를 갖는 터보부호의 Flattening Effect의 성능향상에 관한 연구)

  • 정대호;정성태;김환용
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.6A
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    • pp.533-539
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    • 2002
  • It is well known the fact that turbo lodes has better performance as the number of iteration and the interleaver size increases in the AWGN channel environment. However, as the number of iteration and the interleaver size are increased, it is required much delay and computation for iterative decoding, and caused the flattening effect phenomenon which is very litter BER performance improvement at the arbitrary SNR. In this paper, We proposed the new asymmetric turbo codes, which consist of parallel concatenated turbo codes that use mixed types of component codes with different not only constraint length but also generate polynomial and analyzed its BER performance for log-MAP decoding algorithm with frame size of 128, 256, 512 and 1024 bits, and coding rate of 1/3. As a results of simulation, proposed asymmetric turbo codes verify that its BER performance is superior to conventional symmetric turbo codes. It can be also observed that the flattening effect phenomenon is very reduced by applying the proposed asymmetric turbo codes. It gains respectively 1.7dB ~2.5dB and 2.0dB~2.5dB SNR improvements in the case of short frame(128, 256) and large frame(512, 1024) size for the BER $10_{-4}$>/TEX> region.