• Title/Summary/Keyword: HABITAT SIZE

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Changes in Landscape Characteristics of Stream Habitats with the Construction and Operation of River-Crossing Structures in the Geum-gang River, South Korea (금강에서 횡단구조물의 설치와 운영에 따른 하천 서식처의 경관 특성 변화)

  • Kim, Dana;Lee, Cheolho;Kim, Hwirae;Ock, Giyoung;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
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    • v.8 no.1
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    • pp.64-78
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    • 2021
  • This study was conducted to find out the effect of the construction and operation of river-crossing structures on the habitat landscape characteristics in the Geum-gang River, South Korea. A total of three study reaches were selected in the downstream of the Daecheong Dam: the Buyong-ri reach, which is a control that is not affected by the construction and operation of the weir of the Four Rivers Project and Sejong-bo Weir reach and Gongju-bo Weir reach of the upper and lower sections of each weir that are affected by the weir construction and operation. The habitat type was classified, and then the structural characteristics of the landscape were analyzed using aerial photographs taken before and after the construction of the Daecheong Dam, before and after the construction of the weir, and before and after the weir gate operation. After the construction of Daecheong Dam in Geum River, the area of the bare land greatly decreased, and the area of grassland and woodland increased in the downstream of the dam. In addition, the patch number in the river landscape increased, the patch size decreased, and the landscape shape index and the habitat diversity increased. Therefore, after the construction of the dam, the bare land habitat was changed to a vegetated habitat, and the habitat was fragmented and diversified in the downstream of the dam. After the construction of the weirs, the area of open water increased by 18% in the Sejong-bo reach and by 90% in the Gongju-bo reach, and the landscape shape index of the open water decreased by 32% in the Sejong-bo reach and by 35% in the Gongju-bo reach, and the habitat diversity index decreased to 25% in the Sejong-bo reach and to 24% in the Gongju-bo reach. Therefore, the open water habitat was expanded, the shape of the habitat was simplified, and the habitat diversity decreased according to the construction of the weirs. After water-gate opening of the weir, the bare land that disappeared after the construction of the weir reappeared, and the landscape shape index and habitat diversity index increased in both terrestrial and open water habitats. Therefore, it was found that the landscape characteristics of the river habitats were restored to the pre-construction of the weir by the operation of the weir gate. The effect of weir gate opening was delayed in the downstream than in the upstream of the weir. Although the characteristics of the landscape structure in the river habitat changed due to the construction of the river-crossing structures, it is thought that proper technology development for the ecological operation of the structures is necessary as the habitat environments can be restored by the operation of these structures.

Movement patterns and home range of captive-bred Amur ratsnake (Elaphe schrenckii) juveniles in the natural habitat

  • Kim, Dae-In;Kim, Il-Hoon;Kim, Ja-Kyeong;Kim, Bin-Na;Park, Dae-Sik
    • Journal of Ecology and Environment
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    • v.35 no.1
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    • pp.41-50
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    • 2012
  • To determine the movement patterns, home range, and use of structural features of captive-bred one- or two-year-old Amur ratsnake (Elaphe schrenckii) juveniles in the natural habitat, we radio-tracked a total of 11 juvenile snakes in a mountain valley in Chiaksan National Park, South Korea, between August 21 and September 20, 2010 and between June 13 and July 13, 2011. During the first week of the release, most juveniles moved short distances, daily, but they increased their distances after the first week. The body weight of the juveniles was negatively related with the movement rate (dividing the number of movements by the number of relocations), which was positively related with the mean daily distances moved and the size of both a kernel 50% and 95% home range. During the study period, the juveniles moved daily, approximately 17 m, and the size of the minimum convex polygon and the 50% and 95% kernel home ranges were 1.8 ha, 0.4 ha, and 3.0 ha, respectively. The released captive-bred juveniles were more frequently confirmed underground or on the ground rather than on rocks or on trees. Our results suggest that the body condition of released individuals, the seasonal time of the release, and the existence of available prey and shelters in the habitat should be carefully considered when releasing captive-bred Amur ratsnake juveniles for the rehabilitation of field populations.

Classification of Microhabitats based on Habitat Orientation Groups of Benthic Macroinvertebrate Communities (저서성 대형무척추동물의 서식 특성에 따른 미소서식처 유형화)

  • Kim, Jungwoo;Kim, Ah Reum;Kong, Dongsoo
    • Journal of Korean Society on Water Environment
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    • v.33 no.6
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    • pp.728-735
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    • 2017
  • Many restoration projects are underway to revive disturbed streams. In order to achieve successful stream restoration, a variety of microhabitats should be created to promote biological diversity. Research on biological classification of microhabitats is essential for biological diversity. However, research on classification using only physical environmental factors has been carried out. The purpose of this study is to classify and quantify the microhabitat of the stream by using macroinvertebrates systematically. In this study, eight wadeable streams and four non-wadeable streams were surveyed to identify the benthic macroinvertebrates in these various microhabitats. Among the physical environmental factors (current velocity, water depth, substrate), the particle size of the substrate was the most influential factor in the emergence of the Habitat Orientaion Groups. Among the HOGs, clinger and burrower were highly correlated with physical environment factors and showed the opposite tendency. The distribution of clinger and burrower according to the physical environmental factors showed two tendencies based on the current velocity (0.3 m/s) and water depth (0.4 m). In addition, the particle size of the substrate showed three trends (${\leq}-5.0$, -5.0 < mean diameter ${\leq}-2.0$, > -2.0). Based on the abundance tendency of these two HOGs, the microhabitats were classified into nine types, from a eupotamic microhabitat to a lentic microhabitat. Classification of the microhabitats using HOGs can be employed for creating microhabitats to promote biological diversity in future stream restoration plans.

External Morphology and Habitat of Black Soldier Fly (Hermetia illucens L.) in Korea (아메리카동애등에(Hermetia illucens L.)의 외부형태 및 서식지에 관한 연구)

  • Jeong, Gilsang;Kang, Hyejin;Choi, Hansu;Lee, Yonggu;Jin, Seon Deok
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.584-590
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    • 2018
  • The adults of Hermetia illucens collected in Korea were about the same size as those from their origin. The body part with the largest size variation was the antenna 2 followed by the head width and the abdomen width. It can be the baseline of selection of superior individuals for organic waste decomposition and compost production. In regards to the habitat, the adult Hermetia illucens were collected from 22 of the 51 localities. Although geographical characteristics such as coordinates and altitude may not affect the insects, the presence of organic matters could affect them. The distribution pattern of the insects may act as an indicator of natural recycling of organic wastes.

Investigation of natural habitats for Korean Musk deer (Moschus Moschiferus) (멸종 위기종 한국사향노루의 서식지 조사)

  • Kim, Jong-Taek;Kim, Geon-Joong;Kim, Hyeon-Cheol
    • Korean Journal of Veterinary Service
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    • v.30 no.3
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    • pp.459-466
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    • 2007
  • The Korean Musk deer (Moschus Moschiferus) is endangered due to heavy hunting and Massive destructions of natural habitat. They are included in CITES appendix II. In addition they are designated as a precious natural product in 1968 and listed as endangered species by the Government and Cultural Heritage Administration. At present, the number of musk deer in Korea is smaller than minimum viable population. Without increment of the population size, natural restoration is impossible. It is necessary to develop the artificial growth and re-enforcement methods in order to conservation Korean musk deer. Furthermore, It is necessary to ensure that we have an adequate individual group for artificial growth and re-enforcement. To ensure that we have an adequate individual group, it is necessary to know ecology of musk deer. This study is conducted to confirm and investigate of habitat of musk deer in order to capture individual musk deer. we investigated, confirmed habitats, found traces and captured using trap and decoy. Captured musk deer is male and 5.5 kg, this have canine tooth of 1.5cm, is estimated 15 months old. After capture, we measured each parts of body and tested to research of parasite infection. Strongyloides papillous was founded in the feces. It is essential to get healthy individual and establish of artificial growth technique.

Development of the Estimating Equation for Children's High-Exposure to Habitat's Magnetic Field using Particle Swarm Optimization (Particle Swarm Optimization을 이용한 소아고노출 생활자계 추정식 개발)

  • Hwang, Gi-Hyun
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.5
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    • pp.1085-1092
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    • 2010
  • This paper describes the development of estimating equation for under 16 aged children's exposure to habitat's magnetic field for 24 hours by using particle swarm optimization(PSO) algorithm, which was carried out by using the measured database collected from the exposure survey to Korean habitat's magnetic field as to under 16 aged Korean students such as preschooler, children in elementary school, and children in middle school. Sex, age, residence type, size of habitation site, distance from power line, and power transmission voltage are used as the input data of estimating 24 hour's personal exposure to magnetic field. And distribution of 24 hour's personal exposure to magnetic field, exposure characteristic to magnetic field, and exposure characteristic to magnetic field according to special conditions, are analyzed for under 16 aged children.

Characteristics of woodland changes in an agricultural landscape - The case of Gwangju (농촌경관지역의 산림변화 특성)

  • Lee, Young-Chang;Jung, Woon-Joo;Kim, Keun-Ho
    • Korean Journal of Agricultural Science
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    • v.38 no.3
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    • pp.429-436
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    • 2011
  • Recent landscape changes from human activities, such as agricultural development and urbanisation frequently result in the loss of habitats, the reduction in habitat patch size and an increasing isolation of habitat patches. However, there is little information on woodland changes in agricultural landscapes. Therefore, the aim of this research was to assess spatial characteristics and changes of woodland in an agricultural landscape and how these may have had an impact on ecological process for 33 years. One of the agricultural landscape character units was analysed based on aerial photographs from 1976, 1983, 1994, 2002 and 2009 in Gwangju city. The results indicated that landscape ecological metrics clearly showed that they could be used to monitor changes of woodland ecological conditions during the past 33 years. The results imply that particularly human activities have been leading to the decrease of the mean size of woodland patches and finally result in woodland isolation. These changes may have a negative impact on woodland bird species in the study area. This woodland information can be used to identify the potential and specific needs for setting priorities for conservation planning.