• Title/Summary/Keyword: Pioneer

Search Result 434, Processing Time 0.022 seconds

The Relationship Between Soil Seed Bank and Actual Vegetation (매토종자와 현존식생과의 관계)

  • Yi, Myung-Hoon;Kim, Yong-Shik;Kim, Do-Gyun;Park, Seok-Gon;Shin, Hyun-Tak
    • Korean Journal of Environment and Ecology
    • /
    • v.24 no.6
    • /
    • pp.638-647
    • /
    • 2010
  • This study was performed in order to analyze influences the actual vegetation between the communities of Pinus densiflora and Quercus mongolica in southern Korea to the species composition of the seed bank in the top soil. The soil samples were collected from the studied plots and transported to the Experimental Glasshouse at Department of Landscape Architecture, Yeungnam University and examined the germinated species individual numbers with species composition and germinated individual numbers by species. The overall germination status was the highest in the herbaceous layers than the layers of tree, sub-tree and shrub, respectively. There were no significantly different between numbers of species and individuals and between actual vegetation and seed bank in the two communities. The woody species marked in the seed bank as a pioneer or edge species than in the two communities which are in the stage of mid or late successional species. Although the plant species in the herbaceous layers was highly influenced to the species composition of the seed bank, but no significantly different was showed within the same forest zone and latitudes of Korean peninsula. As the pioneer or edge species of the actual vegetation possibly will be higher the buried in the top soil layer and this phenomenon will influence overall species composition in the seed bank population.

Soil Salinity and Continuum Distribution of Vegetation on the Three Reclaimed Tidal Flats of Kyonggi-Bay in the Mid-West Coast of Korea (한국 중부 서해안 경기만 일대 3개 간척지의 토양 염농도와 식생의 연속분포)

  • Kim, Eun-Kyu;Chun, SoUl;Joo, Young-K.;Jung, Yeong-Sang;Jung, Hyeung-Gun
    • Korean Journal of Soil Science and Fertilizer
    • /
    • v.41 no.2
    • /
    • pp.83-93
    • /
    • 2008
  • Assessing for flora distribution is necessary for land management and environmental research in reclaimed lands. This study was conducted to find out the relationship between vegetation distribution and soil salinity on three reclaimed tidal flats of Kyonggi-bay in the mid-west coast of Korea. We investigated the soil salinity and identified the vegetation at the continuum distribution spots, and describe the characteristics of continuum distribution. On the reclaimed tidal flats, spatial variation of vegetation formed partially, however as the result for connection of each spatial variation along with the soil salinity, continuum distribution formed and it was overlapped edaphic gradient with vegetation distribution, it means that the continuum distribution correspond with soil salinity gradient, as the evidence high salt tolerance species occurred at high saline spots, non salt tolerance species occurred at low saline spots. On the aged reclaimed tidal flats, continuum type was various and also clearly distinguished but it was not clear on the early stage of reclamation. The continuum distribution distinguished sequential and non-sequential type. Sequential type started from high saline zone and connected to low saline zone gradually, on this type, vegetation changed from pioneer halophyte to facultative halophyte and glycophyte along with the salinity gradient. Non-sequential type formed by non-sequential change of soil salinity, on this type, vegetation distribution was non-regular form because it has not changed gradually. In the aged reclaimed land, vegetation wilted zone existed with high salinity, and continuum distribution started from this zone with bare patch.

Spreading and Distribution of Lactuca scariola, Invasive Alien Plant, by Habitat Types in Korea (침입외래식물 가시상추의 확산과 생육지 유형별 분포 특성)

  • Kim, Young-Ha;Kil, Ji-Hyon;Hwang, Sun-Min;Lee, Chang-Woo
    • Weed & Turfgrass Science
    • /
    • v.2 no.2
    • /
    • pp.138-151
    • /
    • 2013
  • This study was carried out to investigate the distribution and habitat types of prickly lettuce, Lactuca scariola of Europe origin for supplying the basic data of management plan. It showed fairly nation-wide distribution although excessive growth was rather limited in the wild. Its habitat types were divided into four types like open fields, roadsides, seashores and riversides. Species diversity examined by species rank-dominance curve tended to increase over riverside > seashores > open fields > roadsides. As a result of analyzing life form, therophytes were more than 50%, means that the habitats of L. scariola were disturbed by human activities etc. Urbanization Index was analyzed 9.1% in roadsides, 7.4% in seashores, 5.8% in open fields and riversides. It has high spread potential with a large number of wind-flying seed per plant. It was evaluated that prickly lettuce was mainly spread along the newly constructed road, expressway and invaded the original ecosystem in the cultivated land as weeds. But it has played a role as a pioneer species in open fields. It is recommended to remove where it has considerable impact on the native plant species of conservation value.

Anatomical Achievement and Thought of Leonardo da Vinci (레오나르도 다빈치의 해부학 업적과 사고)

  • Chai, Ok Hee;Song, Chang Ho
    • Anatomy & Biological Anthropology
    • /
    • v.29 no.2
    • /
    • pp.35-46
    • /
    • 2016
  • Leonardo da Vinci is remembered as the greatest genius of the Renaissance. He left outstanding achievements as an artist, scientist and inventor, and contributes up to today's science. He ranks the best in a variety of fields, such as botany, mathematics, geology, astronomy, geometry and optics. It has well known that Leonardo is an artist, scientist, inventor and philosopher. And he was a great anatomist that dissected dead bodies and animals directly and left many anatomical drawings. He took an interest in anatomy from the point of view of the artist, which is why the human body structure and function to know the sakes were "ignorant of the anatomy should not be upset." Over time, he became interested in the structure and function of the body, even get the human body in a difficult environment; he dissected many the human bodies directly. His scientific inquiry and infatuation made him as an advanced pioneer for more than 100 years, and got enough level to surpass the artistry. Leonardo left about 1,800 anatomical figures of the muscular, skeletal, vascular, nervous and urogenital system, and they are also very scientific and high artistic achievements. The aim of this article is to take a look at Leonardo da Vinci's anatomical achievements and thoughts. In addition, the goal is to knowledge today's anatomists about Leonardo da Vinci's astonishing achievements as a great pioneer in anatomy.

Mechanism of Wetland Formation according to Interaction of River Bed Fluctuation and Plant Success in the Hangang River Estuary (한강하구에서 하도변화와 식물천이의 상호작용에 따른 습지형성 기작)

  • Lee, Samhee;Youn, Sukzun
    • Journal of Wetlands Research
    • /
    • v.24 no.4
    • /
    • pp.320-330
    • /
    • 2022
  • The Hangang river estuary, which is a natural estuary without structures such as estuary barrage, is an ecological pathway connecting the sea and rivers. Accordingly, Hangang river estuary has various species, and there is very valuable. Sediment classification in Hangang river estuary is three-dimensionally and diversely is distributed. Sediment classification in Hangang river estuary is also sensitively changed according to various factors such as climate change and river development. It is typically cause to landform and to develop a compound cross section. In Janghang wetland, the plant success is remarkable according to the morphological change at river bed. The purpose of this study is to identify the mechanism of wetland formation based on the observation on-site. As a result of the observation, Janghang wetland where was artificially created, has been grown according to the river bed change based on the flow rate and the plant success. The viscous surface layer material(fine grains of wash rod properties), which is not the main material(sand) of the river bed, but sub-materials of river bed, jas been settled on the pioneer plants(bolboschoenus planiculmis, etc.). It is an important role in the growth of a compound cross section and a wetland. After the wetland developed to the compound cross section, it is observed that the pioneer plants are transferred to other plant species.

Comparative Tield and Quality of Summe Annual Grasses as Fresh-cut Forage (하형 청예 사료작물의 생산성과 사료가치 비교)

  • Jo, M.H.
    • Journal of The Korean Society of Grassland and Forage Science
    • /
    • v.6 no.3
    • /
    • pp.169-173
    • /
    • 1986
  • This experiment was conducted to provide comparative data on the newly imported thirteen sorghum-sudangrass hybrids(Sorghum bicolor(L.) Moench), TE Goldmaker sorghum hybrid (S. Bicolor (L.) Moench), NC+ 88SS sudangrass hybrid (S, bicolor (L.) Moench), Supermill pearlmillet (Pennisetum americanum (L.) Leeke) and teosinte (Euchlaena mexicana Schrad,) in comparison with the check variety Pioneer 988 sorghum-sudangrass hybrid for dry matter yield, protein content, in vitro dry matter digestibility(IVDMD), and other desirable agronomic characteristics, SX-17 and NC+855 gave significantly higher dry matter yield than the check variety. There was no significant difference in total dry matter yield of the remaining 14 varieties with the exception of teosinte and TE Goldmaker which had the lowest yield. The most varieties were moderately resistant to leaf diseases although differences exist among varieties. No diseases were found in pearlmillet and teosinte, but NC+ 88SS was very susceptible to leaf blight. The mean percent crude protein of sorghum-sudangrass hybrids was lower than that of pearlmillet and sorghum hybrid, but was higher than that of sudangrass hybrid, The IVDMD of G-83F, TE Goldmaker, teosinte and HW 5111 was higher than that of the check variety. There was no consistent relationship between the percent of crude protein and IVDMD of the summer annual grasses.

  • PDF

Changes in NK Activity and CD57-CD16+ Level by Frontal Exposure to Red Photodiode Light

  • Kamei, Tsutomu;Toriumi, Yoshitaka;Kumano, Hiroaki;Ohno, Satoshi;Yasushi, Mitsuo
    • Journal of Photoscience
    • /
    • v.9 no.2
    • /
    • pp.475-478
    • /
    • 2002
  • In zoological research, penetration of light has been reported of the frontal bones of fish, birds, and reptiles, suggesting the existence of physiologically direct photic routes to frontal lobes and/or deep parts of the brain. We studied the influences of frontal exposure to photodiode light on frontal alpha wave and peripheral NK cells. Repetitive exposure of the subject's forehead to a red light diode (660nm) significantly increased the effective amplitude of the frontal alpha waves (using a mean frequency with a range of +1.0 Hz), peripheral NK activity, and the level of CD57-CD16+. Frontal alpha wave activity and the level of CD57-CD16+ increased, suggesting the possibility of a non-invasive procedure for the activation of the frontal lobe and the increase of NK cells. This light is considered to penetrate the frontal bones of humans directly, and to act on the frontal lobe and/or other immunological regulatory centers in the brain, resulting in some neuro-immunological changes.

  • PDF

A Study on the Public Libraries as Life-Long Education Based on the Thought of Melvil Dewey (Melvil Dewey 생애교육의 장으로서 공공도서관 연구)

  • Nam, Tea-Woo
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.48 no.3
    • /
    • pp.511-530
    • /
    • 2014
  • Melvil Dewey has been evaluated as a person of library movement, a man of thought, and a pioneer. However, the life-long achievements as a teacher has not been considered in the domain of library science. The foundations of Dewey's thought of public library can be divided into two categories: school education and home education. Based on these two types of education, Dewey established the major role of public libraries in supporting the life-long education of the public. Regardless of the great achievement of Dewey in education, few research has been conducted. The purpose of this research is to consider the role of libraries from the perspective of life-long education based on the thought of Dewey.

Indoor Mobile Robot Heading Detection Using MEMS Gyro North Finding Approach (MEMS Gyro North Finding 방법을 이용한 실내 이동로봇의 전방향 탐지)

  • Wei, Yuan-Long;Lee, Min-Cheol;Kim, Chi-Yen
    • The Journal of Korea Robotics Society
    • /
    • v.6 no.4
    • /
    • pp.334-343
    • /
    • 2011
  • This paper presents a new approach for mobile robot heading detection using MEMS Gyro north finding method in the indoor environment. Based on this, the robot heading angle measurement scheme is proposed; improved north finding theory and algorithm are also explained. Several approaches are applied to confirm system's precision and effectiveness. In order to find out the heading angle, a single axis MEMS gyroscope to sense the angle between the robot heading direction and the north is used. To reach enough estimation accuracy and reduce detection time, the least square method (LSM) for the signal fitting and parameter estimation is applied. Through a turn-table, we setup a carouseling system to decrease the substantial bias effect on gyroscope's heading angle. For the evaluation of the proposed method, this system is implemented to the Pioneer robot platform. The performance and heading error are analyzed after the test. From the simulation and experimental results, system's accuracy, usefulness and adaptability are shown.

Cosmetic Grinding Revisited (Cosmetic Grinding의 재조명)

  • Lee, Dong-Hwan;Chung, Wounho
    • Journal of the Korean Academy of Esthetic Dentistry
    • /
    • v.24 no.2
    • /
    • pp.134-142
    • /
    • 2015
  • Esthetic dentistry has been developed through the diverse material and technique. Approach and interest in esthetic of anteriors was driven by needs and wants of patients. Alpha and omega of esthetics is determined by patients, as Charles Pincus who is the pioneer of esthetic dentistry described in his article 1967. To meet with wants and needs of patients, dentists suggest possible various treatment options. Cosmetic grinding quoted by Pincus is one of the conservative approaches and provide effective esthetic improvement with minimal invasive concepts. In a high technology era, cosmetic grinding needs to be revisited. Review of some clinical cases shows the value and limitation of it.