• Title/Summary/Keyword: Occurrence ecology

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An analysis on child counseling services of child welfare policy in Korea (한국의 아동복지 정책 분석 -아동상담을 중심으로 -)

  • Ha, Seung-Min
    • Korean Journal of Human Ecology
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    • v.8 no.3
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    • pp.465-476
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    • 1999
  • The purpose of this study was to analyze on child counseling services of child welfare policy in Korea. Furthermore the results of analytic research were done to serve as the basic data for guidance and policy of Korean child welfare in future. The analytic data of this study were used from yearbook of health and welfare statistics(1998), ministry of health and welfare, republic of Korea. The main results obtained were as follows. 1. There were 47 guidance centers for children in Korea, and public guidance centers were 9, and private 38. 2. There were much more guidance centers in Holt Children's Services than in any other centers. 3. In terms of the occurrence of the cases, common children were about 40%, and juvenile delinquents, the scum of the street, and runaway children were from 17 to 20% of the total cases. In conclusion, government and nongovernment should provide various counseling services for the children. The data are discussed with respect to the implication of child welfare policy for attaining counseling services.

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Interpretation of the Paleoclimate Environment using Large Plant Fossil of Peatland in Pyeongtaek, Central Korea

  • Lee, Jin-Hee;Cho, Kyu-Tae
    • Korean Journal of Environment and Ecology
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    • v.29 no.1
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    • pp.81-87
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    • 2015
  • This study was carried out in the peatland for estimating the paleoenvironment based on the analysis from its fossils plant and radiocarbon at the Hwayang-ri, Hyeondeok-myeon, Pyeongtaek-city, South Korea. Variety of fossil was collected from the peatland which could discriminated with naked eye and sorted into seeds, leaves, stems from four-stage of standard sieve. During analysis for the large plant fossil within the peatland, the dead plants were largely divided into 3 fossil zones according to its peatland. In the fossil zone III (the oldest layer; 6,970~6,070 yr $C^{14}$ B.P.), the observation of leaves of hydrophyte such as Trapa sp. and stems of Alnus japonica which appeared in wetland means that the environment was influenced by the climate changes such as rainfall increasing and sea level rise. In the fossil zone II (the middle layer; 6,070~5,800 yr C14 B.P.), the occurrence of Gramineae, Cyperaceae and Fagaceae indicate that the environmental condition might be more or less dry by decreasing rainfall and drop in sea level. The fossil zone I (the recent layer; 5,800~4,540 yr $C^{14}$ B.P.) where lots of herbaceous plants, increasing of Fagaceae, decreasing of A. japonica. and distribution of Pinaceae were showed, was inferred to be repeated both dry and wet environment due to human disturbance.

Effects of Climate Change on the Occurrence of Two Fly Families (Phoridae and Lauxaniidae) in Korean Forests

  • Kwon, Tae-Sung;Lee, Cheol Min;Jie, Okyoung;Kim, Sung-Soo;Jung, Sungcheol;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • v.54 no.1
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    • pp.71-77
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    • 2021
  • Using data from flies collected with pitfall traps in 365 forests on a nationwide scale in Korea, the abundance and distribution changes of two families (Phoridae and Lauxaniidae) in Korean forests were predicted at the genus level according to two climate change scenarios: RCP 4.5 and RCP 8.5. The most suitable temperature for the 17 major genera was estimated using a weighted average regression model. Stichillus and Anevrina displayed the lowest optimum temperature with 7.6℃ and 8.5℃ in annual mean temperature, respectively, whereas Chonocephalus had the highest optimum temperature with 12.1℃. Among thirty genera, seven genera (four from Phoridae and three from Lauxaniidae), which showed their abundance in a bell-type or linear pattern along the temperature gradient, were used for predicting the distribution changes according to the future climate change scenarios. All the taxa of this study are expected to decrease in abundance and distribution as a function of temperature increase. Moreover, cold-adapted taxa were found to be more affected than warm-adapted taxa.

Distributional Characteristics by Habitat Type of Alien Plants - For Gyeongsang Area in Korea - (외래식물의 서식처 유형에 따른 분포특성 - 한국 경상권을 대상으로 -)

  • Lee, Jung-Min;Kim, Eui-Joo;Lee, Hyo-Hye-Mi;Cho, Kuy-Tae
    • Korean Journal of Ecology and Environment
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    • v.54 no.2
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    • pp.142-150
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    • 2021
  • To analyze the distribution characteristics of alien plants in various habitat types, 249 sites were selected from four administrative districts in the Gyeongsang region of Korea. The survey was conducted across nine different habitat types. A total of 115 species of alien plants were collected; comprising 23 families, 73 genera, 112 species, and 3 varieties. Species from the family Compositae were the most common at 33.0%. Raunkiaer's life forms had the highest occurrence rate with 70 species(60.9%) of therophytes(Th) followed by 30 species (26.1%) of hemicryptophytes (H) and 8 species (7.0%) of geophytes (G). The distributions of alien plant species per habitat type were: 81 species on the roadside; 80 species on vacant lots and artificial habitats; 67 species in streams; 53 species in grasslands; 47 species in cultivated lands; and 39 species on the coast. Since 2017, the number of alien plants has increased in Gyeongju-si, Cheongdo-gun, and Pohang-si, and decreased in Ulsan Metropolitan-si. In each region, 614 taxa were observed. The invasive alien species, Sicyos angulatus, Hypocaeris radicata, and Solanum carolinense, were observed for the first time and are expected to further increase the disturbance of the ecosystem.

Density estimation of giant jellyfish (Nemopilema nomurai) using a scientific echosounder (과학어군탐지기를 이용한 노무라입깃해파리(Nemopilema nomurai)의 분포 밀도 추정)

  • Sunyoung OH;Kyoung-Yeon KIM;Seok-Hyun YOUN;Sara LEE;Geunchang PARK;Wooseok OH;Kyounghoon LEE
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.60 no.1
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    • pp.18-26
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    • 2024
  • In this study, we estimated the distribution density of giant jellyfish in coastal waters of Korea in 2023 and compared the occurrence of giant jellyfish over four years. In May, the giant jellyfish were mainly distributed in the waters of the Yangtze River outflow, and in July, they were highly distributed in the west of Jeju Island and near the south coast of Korea. In addition, when comparing the distribution densities of giant jellyfish in Korea over four years, both acoustic and sighting surveys showed that the highest density of jellyfish occurred in 2021.

Distribution of Weeds on Upland Crop Field in Northern Gyeonggi-do (경기북부 밭 잡초 분포)

  • Oh, Young-Ju;Lee, Wook-Jae;Hong, Sun-Hee;Lee, Yong-Ho;Na, Chae-Sun;Lee, In-Yong;Kim, Chang-Seok
    • Weed & Turfgrass Science
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    • v.3 no.4
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    • pp.276-283
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    • 2014
  • This study was conducted in order to investigate the distribution pattern of weeds on upland crop field in northern Gyeonggi-do. The weeds were summarized as 201 taxa including 42 families, 129 genera, 178 species, 1 subspecies, 21 varieties and 1 form. One hundred and thirty one species were classified to annual plants, accounting for 65.1% and 70 species were classified to perennials, accounting for the rest of 34.9%. Compositae was dominant family (21%), followed by Gramineae (12%), Polygonaceae (7%) and Brassicaceae (5%). Among the weeds appearing in the fields of northern Gyeonggi-do, the invasive weeds were classified to 62 species in18 families. The most dominant weed species in the fields were Portulaca oleracea, followed by Echinochloa crus-galli, Amaranthus lividus. Detrended correspondence analysis for investigation of occurrence pattern of weeds by crops revealed the occurrence pattern of weed species in adlay field were different from those in other crop fields. This information could be useful for establishment of weed control methods in northern Gyeonggi-do.

Ecology and Growth of Weeds and Weedy Rice in Direct-seeded Rice Fields (직파재배답(直播栽培沓)에서의 잡초(雜草) 및 적미(赤米) 발생(發生) 생태(生態))

  • Choi, C.D.;Moon, B.C.;Kim, S.C.;Oh, Y.J.
    • Korean Journal of Weed Science
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    • v.15 no.1
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    • pp.39-45
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    • 1995
  • This experiment was carried out at Yeongnam Crop Experiment Station since 1992 to obtain basic information on ecology of weeds and weedy rice in direct-seeded rice fields. Annual grass weeds of Echinochloa sp., Leptochloa sp., Digitaria sp. and Setaria sp.(C4 plant) and weedy rice(C3 plant) were important species in direct seeded rice compared to transplanted rice field. Period of seedling emergence of barnyard grass was varied from 8 days to 20 days depending on seeding date while it was shorter 4 to 6 days than rice. Weed occurrence and the degree of yield loss were varied by cultivation method. In direct seeding method weeds increased 2 to 3 times compared to manual transplanting. The greatest yield loss was recorded in direct seeding(40 to 100%) followed by mechanical transplanting(25 to 35%) and hand transplanting(10 to 20%), in order. Double cropping of rice-barley was reduced weeds about 30% than rice single crop due to alleopathic effect of barley residue or stubble. Weedy rice(red rice) occurrence was closely related with seeding date and tillage methods. Early seeding and reduced tillage enhanced the growth of weedy rice.

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Morphological Characteristics and Ecology of Locusta migratoria (Orthoptera: Acrididae) in Jeonnam Province (전남지역에 발생하는 풀무치(Locusta migratoria)의 형태적 특징 및 발생생태)

  • Choi, Duck-Soo;Ma, Kyeong-Cheul;Kim, Hyo-Jeong;Lee, Jin-Hee;Oh, Sang-A
    • Korean journal of applied entomology
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    • v.56 no.4
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    • pp.421-426
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    • 2017
  • These experiments were conducted to investigate the morphological characteristics, occurrence ecology, host preference, and oviposition of Locusta migratoria to create a forecasting manual in preparation for outbreaks of this species. The sex ratio (female:male) of 274 adult of L. migratoria which occurred naturally in the Muan region of Jeollanam-do was 18.2 : 81.8, 60.9% individuals were of the green type and 39.1% were of the brown type. Body length and body weight were 6.5 cm and 2.8 g for females and 5.0 cm and 1.5 g for males, respectively; body size did not differ between differently colored individuals. Spawning activity in the field was observed from late August to late October. Eggs laid between late September and early October hatched in late May the following year. Female adults fed 3.5 g of corn leaf and male adult was 1.6 g for a day. The host preference of L. migratoria was in the order corn > foxtail millet > millet > silver grass > rice, and preference for silver grass and rice was very low. Pure sand was most favorable for the spawning of L. migratoria, and the cumulative amount of hatching was higher when the soil moisture content was higher after spawning began.

Monitoring Vegetation Structure Changes in Urban Wetlands (도시 내 습지의 식생구조 변화 모니터링)

  • Kim, Na-Yeong;Nam, Jong-Min;Lee, Gyeong-Yeon;Lee, Kun-Ho;Song, Young-Keun
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.26 no.6
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    • pp.135-154
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    • 2023
  • Urban wetlands provide various ecosystem services and are subject to restoration and creation projects due to their increased value in the context of climate change. However, the vegetation structure of wetlands is sensitive to environmental changes, including artificial disturbances, and requires continuous maintenance. In this study, we conducted a vegetation survey of three wetlands created as part of a project to restore urban degraded natural ecosystems and monitored the quantitative changes in wetland vegetation structure using an unmanned aerial vehicle. The vegetation survey revealed 73 species in Incheon Yeonhui wetland, and the change in vegetation composition based on wetland occurrence frequency was 11.5% on average compared to the 2018 vegetation survey results. The vegetation survey identified 44 species in Busan Igidae wetland, and the proportion of species classified as obligate upland plants was the highest at 48.8% among all plants, while the proportion of naturalized plants accounted for 15.9% of all plants. The open water surface area decreased from 10% in May 2019 to 6.7% in May 2020. Iksan Sorasan wetland was surveyed and 44 species were confirmed, and it was found that the proportion of facultative wetland plant decreased compared to the 2018 vegetation survey results, and the open water surface area increased from 0.4% in May 2019 to 4.1% in May 2020. The results of this study showed that wetlands with low artificial management intensity exhibited a tendency for stabilization of vegetation structure, with a decrease in the proportion of plants with high wetland occurrence frequency and a relatively small number of new species. Wetlands with high artificial management intensity required specific management, as they had a large change in vegetation structure and a partially high possibility of new invasion. We reaffirmed the importance of continuous monitoring of vegetation communities and infrastructure for wetlands considering the function and use of urban wetlands, and restoration stages. These research results suggest the need to establish a sustainable wetland maintenance system through the establishment of long-term maintenance goals and monitoring methods that consider the environmental conditions and vegetation composition of wetlands.

Selecting Protected Area Using Species Richness

  • Kwon, Hyuksoo;Kim, Jiyoen;Seo, Changwan
    • Korean Journal of Environment and Ecology
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    • v.29 no.1
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    • pp.14-20
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    • 2015
  • We created species richness maps of mammals, birds and plants using "Nnational Ecosystem Survey" data and identified correlations between species richness maps of each taxa. We examine the distribution of species richness of each taxa and calculated conservation priority rank through plotting species-area curves using an additive benefit function in Zonation. The conclusions of this study are as follows. First, plant showed high species richness in Gangwon province and Baekdudaegan, and mammals showed high species richness at eastern slope of Baekdudaegan in Gangwon province unusually and the species richness of mammals distributed equally except Gyeonggi and Chungnam province. However, birds showed high species richness in the west costal because the area is the major route of winter migratory birds. Second, correlation of each taxa's distribution is not significant. Correlation between mammals and birds is positive but correlations between birds and others are negative. Because mammals inhabit in forest but birds mostly live in coastal wetlands and rivers. Therefore, bird's habitats are not shared with other habitats. Third, the probability of mammals occurrence is very low under 25% in species-area curve, others increase proportionally to area. Birds increase dramatically richness at 10% because bird's habitat is concentrated in coastal wetlands and rivers. Plants increased gently species richness due to large forest in Gangwon province. We can calculate the predicted number of species in curves and plan various conservation strategies using the marginal number of species. Finally, high priority ranks for conservation distributed mainly in Gangwon province and Baekdudaegan. When we compared with priority map and terrestrial national parks, the parks were evaluated as high priority ranks. However, the rank of parks away from Baekdudaegan was low. This study has the meaning of selecting conservation priority area using National Ecosystem Survey. In spite of the omission of survey data in national parks and Baekdudaegan, the results were good. Therefore, the priority rank method using species distribution models is useful to selecting protected areas and improving conservation plans. However, it is needed to select protected areas considering various evaluation factors, such as rarity, connectivity, representativeness, focal species and so on because there is a limit to select protected area only using species richness.