• Title/Summary/Keyword: POPULATION ECOLOGY

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Occurrence Characteristics of Weed Flora in Arable Fields of Korea (우리나라 농경지에 발생하는 잡초 현황)

  • Lee, In-Yong;Oh, Young-Ju;Park, Jung-Soo;Hong, Sun-Hee;Choi, Jun-Keun;Heo, Su-Jeoung;Kim, Eun Jeong;Lee, Chae-Young;Park, Kee Woong;Cho, Seng-Hyun;Kwon, Oh-Do;Im, Il-Bin;Kim, Sang-Kuk;Seong, Deok-Gyeong;Chung, Young-Jae;Kim, Chang-Seog;Lee, Jeongran;Seo, Hyun-A;Jang, Hyung-Mok;Kim, Jin-Won
    • Weed & Turfgrass Science
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    • v.6 no.2
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    • pp.86-108
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    • 2017
  • The nationwide weed survey was conducted in arable land, paddy field, upland, orchard and pasture, over whole country of Korea during 3 years from 2013 to 2015. Also, these survey were conducted in order to determine a change of weed community and to identify a major dominant weed species, and problem weeds. Weeds of arable land were composed of 619 species belonging to 81 families. Weeds occurred in paddy field were 90 species belonging to 28 families, upland weeds were 375 species of 50 families, orchard weeds were 492 species of 63 families and pasture weeds 275 species of 52 families. Among total 81 families, the Asteraceae (15.5%) was the biggest family, followed by Poaceae (13.1%), Fabaceae (5.5%), Cyperaceae (5.2%), Polygonaceae (6.3%), respectively. And these weed species were composed of annual weeds of 209 species (33.8%), winter annual of 102 species (16.4%) and perennial weeds of 308 species (49.8%). Exotic weeds naturalized in Korea were investigated as 166 species. Weed flora in Korean cultivation area have been increased as much as 13 families and 186 species for 10 years compared to 2000~2004 weed survey result of 68 families and 433 species. The increment could be resulted from the change of weed population such as increase of the herbicide-resistant and the difference of investigation method.

Weed Flora Diversity and Composition on Upland Field of Korea (우리나라 밭작물 재배지 잡초 발생 및 분포현황)

  • Lee, In-Yong;Oh, Young-Ju;Hong, Sun-Hee;Choi, Jun-Keun;Heo, Su-Jeoung;Lee, Chae-Young;Hwang, Ki-Seon;Park, Kee-Woong;Cho, Seng-Hyun;Kwon, Oh-Do;Im, Il-Bin;Kim, Sang-Kuk;Seong, Deok-Gyeong;Chung, Young-Jae;Kim, Chang-Seok;Lee, Jeongran;Seo, Hyun-A;Jang, Hyung-Mok
    • Weed & Turfgrass Science
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    • v.4 no.3
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    • pp.159-175
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    • 2015
  • Surveys of weed species on upland fields were conducted in Korea to investigate the occurrence of weed flora from April to May 2014 for winter crop fields and from July to August 2014 for summer crop fields. From the nation-wide survey, 375 weed species in 50 families were identified and classified to 162 annuals, 78 biennials and 135 perennials. Based on the occurrence ratio, the most weed species belonged to Compositae (73 species). 44 and 25 weed species belonged to Poaceae and Polygonaceae, respectively, and these 183 weed species in the most five families accounted for 49% of total weed occurrence. While 287 weed species in 45 families occurred in the winter crop fields, 339 weed species in 47 families occurred in summer crop fields. The most dominant weed species in Korean upland fields were Digitaria ciliaris, followed by Portulaca oleracea, Acalypha australis, Chenopodium album, Rorippa palustris etc. 129 weed species in 25 families were considered as exotic weeds. Based on the importance analysis, the highest value was C. album followed by Amaranthus lividus, Conyza canadensis etc. This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in upland fields of Korea.

Spawning Behavior and Early Life History of Korea Freshwater Goby (Rhinogobius brunneus) (밀어 (Rhinogobius brunneus)의 산란행동 및 초기생활사)

  • Moon, Woon-Ki;Na, Young-Eun;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.38 no.1 s.110
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    • pp.83-94
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    • 2005
  • The objective of the study was to elucidate early life history of Rhinogobius brunneus, based on laboratory observations and field works, along with its courtship and spawning behaviors. The male and female fish matured were sampled for the lab experiments from Gap-Stream, which is one of the tributaries of Geum-River, Korea. The spawning behaviors and courtship of matured adults had a typical pattern; matured males of Rhinogobius brunneus built up spawning nests and had their own territory before the spawning, and the behavior then triggered the egg spawning of female with active courtship. The females attached elliptic egg mass as a single layer, on the stones below the spawning nest. After the spawning, the egg mass was guarded by males only until the hatching. The size of egg fertilized, measured by microscope was about 1.5${\pm}$0.1mm in length and 0.7${\pm}$0.1 mm in the egg's width. According to the lab experiments conducted under four temperature regime, the lapsed time for the hatching was shortened as temperatures increased in the treatments. On the contrary to the hatching time, the average length of newly hatched larvae showed a reverse relation with water temperature. The larvae, considered a final stage of the early life history was about 3.6 mm in total length for water temperature of $18^{\circ}C$, whereas they were between 3.1 mm and 3.2 mm for over $25^{\circ}C$. This indicates that higher water temperature may decrease the growth rate in the early life history. These results may provide valuable information for the population conservation and ecosystem protection under accelerated water pollution and habitat degradations in Korea.

Modulation of Immune Parameters by Aging Process (노화에 따른 면역지표의 변화에 관한 연구)

  • Lee, Ji-Hye;Jung, Ji-Hye;Kim, Hyun-Sook
    • Journal of Nutrition and Health
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    • v.43 no.2
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    • pp.152-160
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    • 2010
  • The purpose of this study was to investigate the effects of aging process on the immunity in human subjects. In this investigation, nineteen families of three generations (daughters on college age, their mothers, and grandmothers) participated to avoid genetic variation among individuals. Dietary food records, anthropometric measurements and biochemical assessments of serum nutrients were used to evaluate the nutritional status of subjects. The immune parameters of subjects were assessed by the total and differential WBC count. Total B and T lymphocytes, and T cell subsets were quantified by flowcytometer. Serum immunoglobulin G, A, M concentrations were also measured as an index of humoral immunity. The result of this study can be summarized as follows: 1. Along with the aging process, body fat was found to be increased whereas lean body mass and total body water were diminished. Since there were no significant difference in serum vitamin E levels in all age groups, serum retinal concentrations tended to decrease as one gets old. 2. Although total number of T lymphocytes seemed to be unchanged, B lymphocytes and NK cell numbers were increased by aging. The Percentage of CD8 + lymphocytes was lower in the elderly subjects compared with the younger, resulting in higher ratio of CD4 +/CD8 + lymphocytes in the elderly. Serum Ig G and Ig A levels remained unchanged, but IgM levels were significantly decreased as the age processes continue. Taking all together, it could be suggested that the alteration of immune cell population by aging is selective and possibly nonage factors such as nutrition may be attributable to the change of immunity in the elderly. The nutritional status and aging process may selectively affect both the cell-mediated (CD8 +, CD4 + CD8 + ratio, NK cell) and humoral (B lymphocyte, Immunoglobulin M, G) immune parameters in human subjects.

Habitat Utilization Change of Crane Species against the Increasing Anthropogenic Structure after Released from Civilian Control Zone; CCZ in Cheorwon, Rep. of Korea (철원 민간인통제지역 해제 이후 인공시설물 증가에 따른 두루미류 분포변화)

  • Yoo, Seunghwa;Joo, Sungbae;Lee, Kisup;Kim, Suho;Kim, Dongwon;Kim, Hwajung;Kim, Jinhan
    • Journal of Environmental Impact Assessment
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    • v.29 no.1
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    • pp.1-7
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    • 2020
  • This study aims to evaluate the effect of artificial facilities constructed afterthe release of the civilian controlled zone (CCZ) in Cheorwon on the inhabitation of cranes. The study site was released from the CCZ in 2012, and several barns have been built since 2017. The average number of Red-crowned Cranes was 9.3±4.3 individuals (±Standard Deviation) in the period before the release of the CCZ from 2009 to 2012, and it decreased by ca. one third of Red-crowned Crane's average individuals were showing 3.5±0.5 individuals after release. The average number of White-naped Cranes also appeared to be decreased by ca. 90% from 63.3±24.6 to 6.0±6.0 individuals. This results suggest that the construction of greenhouses and barns after the releasing of the CCZ affected the decrease of the population of these two crane species. In the case of Red-crowned Crane, the core area tended to move away from the area where barns were built. However, the distribution range of Red-crowned Cranes did not change significantly we expected because the study area was not their favorite place since 2012 when the area was released from the CCZ. The density of the White-naped Crane was relatively high even in the area where greenhouses were built, but after 2017 when the barn was built intensively, core habitat of crane became shrink and fragmented. These results suggest that both Red-crowned Cranes and White-naped Cranes response sensitively against habitat change due to the construction of barns. Since the release of the CCZ, the construction of the greenhouse has been influenced on the distribution of cranes, but subsequently, the construction of the barn seems to have caused a bigger change in their core habitat because the passage of people to barns is more frequent than the greenhouses.

Distribution Characteristics and Dynamics of the Lindera sericea Population at Mt. Mudeung, Mt. Cheonbong and Mt. Chogye (무등산, 천봉산 및 조계산에서 털조장나무 개체군의 분포특성과 동태)

  • Lim, Dong-ok;Choi, Dea-hun;Yun, Hong-gyun
    • Korean Journal of Environment and Ecology
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    • v.29 no.4
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    • pp.570-579
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    • 2015
  • Lindera sericea, which belongs to genus Lindera in the Lauraceae family, is labeled under Least Concerned (LC) among Korean rare plants, floristics specific species IV grade and also flagpole species of the Mudeung National Park. It is distributed in Mt. Mudeung, Mt. Cheonbong and Mt. Chogye within gradients from $12^{\circ}$ to $51^{\circ}$. The slope area is from northeast to northwest sides and the altitude range of distribution site is between 220 m and 533 m. The vascular plants in the quadrate where Lindera sericea were studied were identified as a total of 72 taxa; 37 families, 54 genera, 66 species, 5 variants and 1 forma. Among the floristics specific species, IV grade species was Lindera sericea and III grade species were Stewartia pseudocamellia and Acer palmatum. Korean endemic species were Stewartia pseudocamellia and Carex okamotoi. As for the vegetation group, Quercus mongolica and Q. serratak - Lindera sericea, Styrax japonicus populations were found in Mt. Mudeung area where Lindera sericea appeared, Stewartia pseudocamellia-Lindera sericea and Sasa borealis populations were found in Mt. Cheonbong areas, Carpinus laxiflora - Lindera sericea and Sasa borealis populations were found in Mt. Chogye area, and Stewartia pseudocamellia-Lindera sericea and Sasa borealis populations were found in Songgwangsa area. A total number of 662 Lindera sericea individuals were examined. The number of trees with 1 trunk including younger individuals was 353 (53.32%), and the number of trees with 2 to 5 stems was 270 (40.79%). The number of trees with the greatest number of sprouts was 27. Of 662 trees in total, the total number of sprouts was 1,198. Among these, 699 trees (58.34%) were between 50 cm and 150 cm in height. The tallest tree was 585 cm. The most common root-collar diameter of sprouts (992, 82.81%) was under 1 cm, followed by the sprouts with collar diameter from 1.0 to 1.5 cm(156, 13.2%). Among them, the largest root-collar diameter was 3.2 cm. This Lindera sericea specimen had the tallest trunk (565 cm) which was torn lengthwise on one side. Its root and breast parts were decayed by 50% and 25 respectively. Some branches of the three trunks that were more than 4 m in length were dead in the apical portion. Therefore, it is proposed that the Korean Lindera sericea maintains an apical dominance tree type while showing morphological adaptation as a typical shrub because it autonomously decays some branches and trunks over a certain height while increasing the number of its sprouts.

Avifauna and Management of Breeding Season in Taeanhaean National Park (태안해안국립공원의 번식기 조류상과 관리)

  • Paik, In-Hwan;Jin, Seon-Deok;Yu, Jae-Pyoung;Paek, Woon-Kee
    • Korean Journal of Environment and Ecology
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    • v.24 no.2
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    • pp.139-146
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    • 2010
  • The survey was done in order to find what kinds of birds visit Taeanhaean National Park during breeding season, where we fixed up 10 coastal areas and islands within the National Park. Three groups concurrently performed the field research from 5th to 9th of July in 2009. Total 58 species and 7,323 individuals were recorded in Taeanhaean National Park. 48 species including 6,187 individuals were observed in coastal areas and 33 species including 1,136 individuals in island areas. The most dominant species in the National Park are Larus crassirostris which accounts for 60% of the birds inhabiting there, and they seem to have been bred in the islands near the National Park. The birds observed only around the coastal areas include Anas poecilorhyncha, Fulica atra, Egretta intermedia and the others which consist of 25 species and amount to 318 individuals, and the birds found exclusively in island areas include Phalacrocorax filamentosus, Apus pacificus¸ Locustella pleskei and other birds, which consist of 10 species and the number of those individuals observed was 308. The inhabited islands areas such as Gauido were characterized by high ratio of waterbird population, which seems to be correlated with the factors such as the extent of island, the richness of water resources, and the diversity of habitats. Based on the data collected during the research and other data from the previous observations, the kinds of dominant species remain nearly unchanged. And in spite of the oil spill accident in 2007, the increase in the number of waterbirds compared to 2004 may be the evidence that the area is recovering from the environmental pollution. At present, the tidal power plants are being built or scheduled to be built and large-scale reclamation is also under way. What is worse, those areas are seeing the increase of pension construction, which is likely to be the potential cause of damage and disturbance against some key habitats for the waterbirds. Therefore, it is a major priority that we build the bird information system to efficiently manage the knowledge-based asset collected from bird-watching groups and to better monitor the areas that need enhanced database through which the National Park can be appropriately administered.

Early Life History and Reproductive Ecology of Mandarin Fish, Siniperca scherzeri (Pisces, Centropomidae) in Soyang Lake (소양호산 쏘가리 Siniperca scherzeri (Pisces, Centropomidae)의 산란 생태와 초기 생활사)

  • Lee, Wan-Ok;Lee, Jong-Yun;Son, Song-Jung;Choi, Nack-Joong
    • Korean Journal of Ichthyology
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    • v.9 no.1
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    • pp.99-107
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    • 1997
  • The early life history and reproductive ecology of Siniperca scherzeri were studied to obtain fundamental information in aquaculture and reinforcement of natural population in Soyang Lake, Buk-myon, Chunchon-shi, Kangwon-do from June to October 1996. Symptric species with adult fishes (+1 ages) of Siniperca scherzeri were 11 species belonging to 6 families and 10 genera and those with Juveniles (2~3 months) were 5 species belonging to 4 families and 5 genera. The sex radio of this species were 1 (female, 85) : 1.24 (male, 105). Adult and juvenile of this species were predominantly piscivores. Bluegill, Lepomis macrochirus, Zacco platypus, common carp, Cyprinus carpio, unidentified fish and shrimp were important components of the food items. The spherical eggs were demersal and separative without a colorless transparent chorion and slightly yellowish yolk containing one large oil globule (0.5~0.7mm). The egg just after fertilization were measuring 1.72~2.05mm (n=30), and expanded to 2.27~2.58mm (n=30) in diameter after 30 min. Hatching occurred 130~155 hrs after fertilization at water temperature of $20{\sim}25^{\circ}C$ and newly hatched larvae measuring 5.5~7.1mm in total length. In the newly hatched larvae, numerous branched malanophores were distributed on the yolk and abdomen of caudal peduncle. In ten-day old larvae, the yolk was mostly absorbed and the head spines and the teeth were well developed. All fin rays were formed and total length of the larvae were reached 13.6~15.6mm at 20 days after hatching. In fifty-five day old larvae were similar in both body shape and color to adult. The juvenile stage at 4 months after hatching were attained 86.4~95.3mm (n=7) in total length and 8.77~14.78g (n=7) in body weight.

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Development of Ecological Restoration Model Consider Analysis on the Vegetation Structure of Burned Area (산불지역 식생구조 분석을 통한 식생복원 모델 개발)

  • Kim, Jeong-Ho;Lee, Soo-Dong
    • Korean Journal of Environment and Ecology
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    • v.21 no.5
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    • pp.400-414
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    • 2007
  • This study has analyzed the vegetation structure to suggest a vegetation ecological restoration model by using the case of the afforestation for erosion control area with Pinus koreaiensis and Betula platyphylla, etc., on the hills of the Young-in mountains after its great fire in 2000. Of the area having a dimension of $1,152,404.3m^2$ selected as a survey site for the existing vegetation, the forest fire area accounted for 69.2% among which, brushwoods accounted the most for 24.67%. As a result of analysis of the 27 surveyed unit plots[unit dimension: $100m^2$] set up in consideration of the existing vegetation pattern and damaged state from the forest fire, the surveyed area was classified into 10 communities. Shrub layer's vegetation was found to be dominant in forest fire areas and the surveyed sites were classified into 5 plant communities, i.e. P. koraiensis community, Quercus variabilis community, P. thunbergii community, Q. serrata community, B. platyphylla community in forest fire areas, while non-forest fire areas were classified into 5 plant communities, such as P. densiflora community, Q. acutissima community, Q. serrata community, Q. mongolica-Q. serrata community, B. platyphylla community. Species diversity of forest fire areas was $0.3679{\sim}0.5907$ and that of non-forest fire areas was $0.5728{\sim}0.8865$. In addition, the number of the species in the forest fire areas was $5{\sim}8$ and that of non-forest areas was $8{\sim}12$; however, the population of forest fire areas$(156{\sim}456)$ was higher than that of non-forest fire areas$(61{\sim}227)$. In the analysis of growth density per layer$[of\;100m^2]$, there appeared $1{\sim}8$ trees of Q. mongolica and $3{\sim}5$ trees of Q. serrata in the upper layer species; $2{\sim}4$ trees of Q. serrata and one tree of Q. mongolica in the canopy layer. As for the characteristics of soil, acidity of forest fire areas was pH 5.45 and that of non-forest fire was pH 5.25. By setting up the middle D.B.H range of Q. mongolica-Q. serrata community as the vegetation restoration model, planting species, planting density and planting models are suggested.

A Study on the Estimation of Ecological Footprint in Gyeongsangbuk-do for Comparison of Environmental Capacity of Each Local Government (자치단체별 환경용량 비교를 위한 경상북도지역 생태발자국 추정연구)

  • Kang, Kee-Rae;Kim, Hee-Chae;Kim, Dong-Pil;Oh, Hyun-Kyung;Cho, Kwang-Jin;Shin, Young-Ho
    • Korean Journal of Environment and Ecology
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    • v.28 no.6
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    • pp.769-778
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    • 2014
  • The rapid urbanization and increase in population due to industrialization have led to the extension of cities and the reduction in naturality as a necessity. Now, it is the biggest threat to virtuous circle of ecosystem. With the expansion of common recognition that this ecological crisis would be accompanied by the crisis of mankind, many countries all around the world are conducting researches to indicate the optimum consumption level of individual as an index in addition to cross-national environmental indicators such as ESI, EPI and SDI, by measuring environmental consumption of state, local government or individual, and comparing each region. Based on this background, this research was carried out to estimate the environmental capacity of 23 local government in Gyeongsangbuk-do. The result of EF estimation showed that EF value necessary for life per head in Gyeongsangbuk-do was 0.9534, and it showed an ecological deficit of 25.3 percent when analyzing it in consideration of the ecological capacity. Also, among the local governments in Gyeongsangbuk-do, Youngduk-gun displayed the highest EF, and Ulleung-gun displayed the lowest EF. But when analyzing the ecological deficit in consideration of the ecological capacity of each region, Gumi-city showed the greatest ecological deficit, and Youngyang-gun showed the biggest ecological capacity. The environmental capacity estimated in this study is to digitize the ecological capacity and ecological deficit of each local government in Gyeongsangbuk-do. The estimated optimum environmental capacity of each local government suggests the scale of environmental preservation and proper development and furthermore, could be used as fundamental data for persuading members of each local government when selecting a location of development facility or preservation area.