• Title/Summary/Keyword: forestry history

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Reproductive Maturity Onset and Tree Size in a Garcinia kola (Heckel) Coastal Humid Tropical Climate Plantation

  • Henry Onyebuchi Okonkwo;Olubunmi Ayokunle Koyejo;Joseph Okechukwu Ariwaodo;Nsien Iniobong Bruno
    • Journal of Forest and Environmental Science
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    • v.39 no.2
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    • pp.73-80
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    • 2023
  • Little is known of the life history of Garcinia kola; the objective of this study, therefore, was to assess the fruiting age and tree size of the species in a coastal humid tropical climate plantation condition. A total 103 trees were used in the study viz; 80 ten-year-old trees at reproductive maturity onset and 13 thirty-year-old trees with several cycles of reproduction that constitute two independent variables. Data collected were age of onset of flowering and size at reproductive maturity onset. Relative size at reproductive maturity onset (RSOM) was estimated as size at reproductive maturity onset (SOM) divided by asymptotic maximal size (AMS). Data analysis was conducted using pairwise t-test and principal component analysis (PCA). Reproductive maturity onset (flowering) was recorded in the ten-year-old stand eight (8) years after planting. Mean size at reproductive maturity onset (SOM) was height 5.32±1.7 m, dbh 0.11±0.03 m, total number of branches was 29.6±7.3, crown depth 5.24±1.05 m, crown diameter was 4.78±0.7 m, branch diameter 0.098±0.01 m, leaf length 0.13±0.02 m, leaf breadth 0.37±0.01 m, twig length 0.35±0.11 m and leaf per twig 6±0.84 and asymptotic maximal size (AMS) was height 19.85±0.76 m, dbh 0.95±0.09 m, total number of branches 62±5, crown depth 18.83±0.7 m, crown diameter 12.5±1.64 m, branch diameter 0.5±1.6 m, leaf length 0.16±0.023 m, leaf breadth 0.45±0.12 m, twig length 0.37±0.11 m and leaf per twig 19±7.5. Pairwise t-test analysis showed there was significant differences between SOM and AMS in all growth factors except leaf length, leaf breadth, and twig length. Highest relative size at reproductive maturity onset (RSOM) was recorded in leaf length 0.82, twig length 0.82, and leaf breadth 0.80, while, the lowest was branch diameter 0.11. Four components out of the total of eleven were extracted to explain the relationship in RSOM: Principal component one (PC1) explained 37.23%; PC2 26.4%, PC3 22.73%, and PC4 13.64%.

Development and Situation of Chinese Forest Resources

  • Cheng, Ming;Chun, Su-Kyoung
    • Proceedings of the KSFDT Conference
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    • 2006.04a
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    • pp.115-125
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    • 2006
  • China has a very large area, but the total and average amount of forest resources are always relative scarcity, retrospect the forest history, when the activities of human beings existed on the earth, the forest resources began to reduce gradually, it indicates that the amount of the forest resources have grate connection with the activities of human beings, especially from the foundation of New China, long term out-of- order logging and unsustainable development make the forest resources and ecological environment be destructed seriously. However, although Chinese forest resources still face a large number of complicated problems, it has already begun to recover and been into the right orbit through listing and analysis a series dates. Additionally, six key forest resources program's launching and the strategy shifting will take china enter a bright future.

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A Taxonomic Review of the Genus Athalia (Hymenoptera: Tenthredinidae: Athaliinae) from South Korea

  • Park, Bia;Choi, Jin-Kyung;Wei, Meicai;Lee, Jong-Wook
    • Animal Systematics, Evolution and Diversity
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    • v.33 no.2
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    • pp.100-111
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    • 2017
  • The species of the genus Athalia Leach from South Korea are reviewed. Six species are listed, one of which is a new record from South Korea (Athalia tanaoserrula Chu and Wang). In South Korean Athalia, we were not able to find any specimens of A. kashmirensis Benson, while many specimens identified as such were a misidentifications of A. tanaoserrula. Therefore, we think that A. kashmirensis should be excluded from the faunal list of South Korea. A key to the species of South Korean Athalia, diagnosis, photographs of the diagnostic characters, distribution and recorded hosts for each species are also provided.

Research on Environmentally-Sound Forest Road Construction( I ) -Recently forest road conservation in Japan- (유역(流域)의 환경보전(環境保全)을 고려한 합리적인 임도시공(林道施工)에 관한 연구(硏究)( I ) -일본에 있어서 최근의 임도사업(林道事業)을 중심으로-)

  • Chun, Kun-Woo;Ezaki, Tsugio;Oh, Jae-Man
    • Journal of Forest and Environmental Science
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    • v.12 no.1
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    • pp.26-36
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    • 1996
  • In our country, nation-wide forest road works are being carried out as one of the efforts to bolster the international competitiveness of agriculture, however such environmental problems as sediment discharge and water quality degradation accompany such efforts more often than not. Hence, in this research report, we compile and analyze the Japanese sources dealing with the "research direction of the forest road construction", "environmental impact assessment upon the watershed of the forest road construction", "environmentally-sound forest road construction and its research method" in consideration of the fact that natural environment of Japan is similar to that of our country and Japanese forest road works has a long history. We hope that this report be useful to the reasonable watershed management and the environmentally-sound forest road works.

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Distinguishing the Effects of Environmental Stress and Forest Succession on Changes in the Forest Floor

  • Arthur, Mary A.;Ruth D. Yanai
    • The Korean Journal of Ecology
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    • v.23 no.2
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    • pp.83-88
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    • 2000
  • When interpreting change over time in forest ecosystems, distinguishing the effects of forest succession from the effects of environmental stress can be difficult. The result may be a simplistic interpretation. citing a specific successional or environmental cause of forest change when both types may be occurring. We present two case studies of changes in the forest floor in northern hardwoods. First, the belief that 50% of soil organic matter is lost in the first 20 years after logging was based on a study comparing northern hardwood stands of different ages. We resampled a series of 13 such stands after an interval of 15 years, and found that the young stands were not, in fact. losing organic matter as rapidly as predicted from the original chronosequence study. The pattern of higher organic matter content in the forest floors of older stands compared to young stands could be equally well explained by changes in logging practices over the last century as by the aging of the stand. The observed pattern of forest floor organic matter as a function of stand age was previously interpreted as a successional pattern, ignoring changes in treatment history. In the second case study, observed losses of base cations from the forest floor were attributed to cation depletion caused by acid rain and declining calcium deposition. We found that young stands were gaining base cations in the forest floor; losses of base cations were restricted to older stands. Differences in litter chemistry in stands of different ages may explain some of the pattern in cation gains and losses. In this case, the contribution of successional processes to cation loss had been overlooked in favor of environmental stress as the dominant mechanism behind the observed changes. Studies of environmental stress use repeated measures over time. but often don't consider stand age as a factor. Studies of successional change often assume that environmental factors remain constant. We were able to consider both forest succession and external factors because we repeatedly sampled stands of different ages.

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Application of Mycorrhizal Research to Agriculture and Forestry (균근연구(菌根硏究)의 농림업(農林業)에의 응용(應用))

  • Lee, Kyung Joon;Lee, Don Koo;Lee, Won Kyu;Koo, Chang Duck
    • Journal of Korean Society of Forest Science
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    • v.59 no.1
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    • pp.121-142
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    • 1983
  • Recently mycorrhizal research has been one of the most fast-growing research areas in modern plant science and microbiology. The application potential of mycorrhizal techniques to agriculture and forestry is enormous in view of the ubiquitous nature of mycorrhizae and known benefits of mycorrhizae to host plants. Unfortunately, very few scientists in Korea are currently involved in mycorrhizal research. When a team of American plant pathologists visited Korea in September 1982 to participate in the Korea-U.S.A. Joint Seminar on Forest Diseases and Insect Pests, they were surprised by the principal author's statement that there was no single research project on mycorrhizae sponsored by Korean government or any scientific institutions. The author initiated a few years ago a research project on the ecology of tree mycorrhizae with a foreign financial support. Major areas of interest were survey of ectomycorrhizae in relation to soil fertility, taxonomic distribution of mycorrhizae among woody plants, identification of ectomycorrhizal fungi, and growth response of woody plants to artificial inoculation. In spite of the enormous application potential of mycorrhizae to agronomic plants, the subject of mycorrhizae has not been recognized by Korean agronomists, foresters or pathologists. The purpose of this review rather written in Korean is to introduce the techniques of mycorrhizal research to Korean scientists and to urge them to participate in challenging new scientific field which might bring us a remarkable increase in crop productivity and tree growth through manipulation of this unique symbiosis. In this review, following topics were discussed in the same order: introduction; brief history of mycorrhizal research; morphology and classification of mycorrhizae; distribution of mycorrhizae in plant kingdom and in soil profile; physiology of mycorrhizae (functions, mineral nutrition, mycorrhizal formation); interaction of mycorrhizae with soil-born plant pathogens. mycorrhizae in nitrogen-fixing plants; application of mycorrhizal techniques to nursery practices (isolation, culture, inoculation, and response); prospect in the future.

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An Analysis of the Experience of Users of National Ecological and Cultural Exploration Routes Using Big Data - A Focus on the Buan Masil Road and Gunsan Gubul Road - (빅데이터를 활용한 국가생태문화탐방로 이용자의 경험분석 - 부안 마실길과 군산 구불길을 대상으로 -)

  • Lee, Hyun-Jung;An, Byung-Chul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.23 no.6
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    • pp.151-166
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    • 2020
  • Various experience keywords were derived through text mining analysis of two National Ecological and Cultural Exploration Routes. The results of this study were drawn as follows: The interaction between the experience keywords was analyzed by the degree centrality, closeness centrality, and betweenness centrality value calculated through the centrality analysis of the research site experience keywords. First, In the text mining analysis, 'walking' appeared as the top keyword in the I, II, and III periods of the two target areas. The keywords related to the stay type of "rental cottage" and "recreational forest" were derived for Masil Road in relation to accommodation facilities. However, the keywords related to the accommodation were not derived in Gubul Road. Second, as a result of the centrality analysis, the degree centrality of the keywords "walking", "sea", "look", "salt flats" of Masil Road and "walking", "lake" and "park" of Gubul Road was high. The keywords located at the center are "walking" and "sea" in the Masil Road, and "walking" in the Gubul Road. As an influential keyword, Masil Road is "experience" and Gubul Road is "history". Third, According to the results of the analysis, the keywords that appeared at the top of the Gubul Road are derived from the keywords related to the 1 ~ 8 course, and it is judged that the visitors are visiting the 1 ~ 8 course trail evenly. However, the Gubul Road only appears in the top keyword only for a few courses. Through this, it seems that three courses are intensively visited as the main course of 6 Gubul Road, 6-1 Gubul Road, and 8 Gubul Road.

History of Biology Education in Korea During the Periord of 1880-1945 (1880-1945 년간의 한국 생물교육의 역사)

  • 김훈수
    • Animal Systematics, Evolution and Diversity
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    • v.10 no.1
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    • pp.97-123
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    • 1994
  • The author devided th period of 1876-1945 into three epochs ; the Opening of Ports in 1876 -before the Political Reform in 1894 , the Political Reform- the Japanese annexation of Korea in 1910 , and the Epoch of Japanese Colony during 1910-1945. As civilization through including educational reform rised. The modern school system began to be introduced nongovernmentally and governmentally to Korea in the 1880's without any school laws. Were chronologycally established school regulation by Korea Government in 1895-1893, school laws by Korean Government under the supervision of the Japanese Residency-General of Korea in 1906-1910, and the educational laws of Korea by the Japanese Government-General of Korea in 1911-1943. In these epochs, the numbers of elementary , secondary and higher educational institutions and the numbers of pupils and students had increased slowly. Japanese had developed sonwhat primary education and secondary technical education, but it had checked extremely the Korean peoples to receive secondary liberal education and higher education, On the epoch of Japanese colony, Japanese occupied nearly half of elementary school teachers, almost of public secondary school teachers educated in Japan, and nearly all of professor educated in Japan in public and national colleges which were technical, and in one imperial university . Forty or more Korean teachers taught natural history chief at private secondary schools for Koreans , more than half of them being graduates of colleges of agriculture and forestry in Korea and Japan. The author mentioned curricula , and subjects and textbooks connected with biology of elementary, secondary and higher educational institutions. The pup8ls and students received biological knowledge through learning sciences at primary schools ; natural history (plants, animals and minerals ) at secondary schools including normal schools ; botany, zoology, genetics and major subjects related with biology such as anatomy, physiology, bacteriology, pland breeding at medical colleges and colleges of agriculture and forestry. There were no departments of biology , botany or zoology in Korea. Only seven Koreas graduated from departments of biology, botany or zoology at imperial universities in Japan. Some of them played the leading parts to develop education and researches of biology in the universities after 1945 Liberation.

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Forest Administration in the United States of America

  • Navon, Daniel I.
    • Journal of Korean Society of Forest Science
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    • v.76 no.3
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    • pp.275-294
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    • 1987
  • In the United States, forest administration is a constantly changing complex of policies, programs, and management regulations. Forest administration is the product of a brief but tumultuous history during which much of the forests which once covered half the land were coutover for farms, industry, and cities. In the last 15 years, forest administration has been increasingly dominated by concerns for maintaining an ecological balance. Current forest administration is deeply rooted in the American traditions of decentralized federalism and free enterprise, yet combines state socialism and private capitalism. The major elements of U.S. forest administration consist of : 1) programs and policies on taxation, professional education and research, and "cooperative forestry", 2) state controls on forest practices for privately owned lands, and of federal policies and regulations for the management of federal lands. The federal Forest Service has played a lead role in developing and implementing national forest policies and programs. Since the end of World War II, the national forests managed by the Forest Service for multiple use have provided and ever growing fraction of domestic timber needs. In the coming decades, cultural and social trends may force a change in management policy on federal land, reducing the importance of timber harvesting in relation to amenity values.

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Epidemiological characteristics of Salmonella spp. isolated from different stages of commercial swine farms

  • Suh, Dong Kyun;Jung, Suk Chan
    • Korean Journal of Veterinary Research
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    • v.45 no.2
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    • pp.179-183
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    • 2005
  • Epidemiological characteristics of a total of 48 swine herd with diarrhea or a history of diarrhea in Gyeongsang-do between 1999 and 2000 were performed to evaluate the prevalence of Salmonella spp., their serotypes and antibiotic resistance patterns with respect to the different stages of swine production system. A total of 139 Salmonella spp. (21%) were isolated from 662 fecal samples and the overall herd prevalence of Salmonella spp. ranged from 12.5% to 88%. The average prevalence of Salmonella spp. from swine stages of suckling/nursery, grow/finisher and sow stage were 25.7%, 19.2% and 18.4%, respectively. Ten serotypes of Salmonella spp. were identified with a predominance of S. Typhimurium, S. Derby and S. Agona. Twenty-five isolates (18%) were found to be untypable. One hundred and two Salmonella isolates (73.4%) resistant to more than 1 antibiotic were characterized by 24 diverse resistance patterns, and their frequency of antibiotic resistance was highest in grow/finisher stage (83.3%). Resistance to tetracycline (TE; 67.6%), sulfamethoxazole (SU; 46.8%) and streptomycin (ST; 28%) was most common and the most common resistance patterns were TE SU (31.4%), TE (21.6%) and TE SU ST (20.6%) in order.