• Title/Summary/Keyword: habitat fragmentation

Search Result 99, Processing Time 0.028 seconds

A Study on the Correlation between Road-kill Hotspot and Habitat Patches (야생동물 서식지 패치와 로드킬 핫스팟의 상관관계 연구)

  • Seok, Sangmuk;Lee, Jiyeong
    • Journal of Environmental Impact Assessment
    • /
    • v.24 no.3
    • /
    • pp.233-243
    • /
    • 2015
  • The ecosystem fragmentation due to transportation infrastructure causes road-kill phenomenon. When making policy for reducing road-kill it is important to select target-species in order to enhance its efficiency. However, many corridors installed in Korea have been raised issues about their effectiveness due to lack of considerations such as target-species selection, site selection, and management, etc. In this study, we are to grasp relationship between road-kill area and habitat patches and suggest that spatial location of habitat patches should be considered as one of the important factors when making policy for reducing road-kill. Habitat patches were presumed from overlying suitability index that chosen by literature review and road-kill hotspot was determined by Getis-Ord $G_i^*$ analysis. Afterwards, we performed a correlation analysis between $G_i$ Z-score and the distance from habitat patches to the roads. As a result, there is a negative correlation between two variables, It affects the $G_i^*$ Z-score going up if the habitat patches and the roads become closer.

The Existing Conditions and Problems of Ecological Corridor in Korea - Focusing on Planting Species - (생태통로 식재수종의 현황 및 문제점 고찰)

  • Kim, Myoung Soo
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.8 no.1
    • /
    • pp.17-26
    • /
    • 2005
  • Ecological corridor is the facility to connect two habitats fragmented by roads, dam, housing and industrial area. Critics of faunal corridors have suggested that they are simply an untested application of unproved island biogeography theory. But, everyone agree that ecological corridor is important useful structural components that help animal movement in fragmented landscapes. There are 52 ecological corridors in Korea. We investigated 43 ecological corridors of these and recorded the size of corridor, planting species, management and growth condition. We compared planting species to nearby exiting vegetation species and structure. We found that there are no considerations for many aspects of planting, for example, planting species, structure, animal migration and behavior, surrounding vegetation etc. Expecially, It was ignored management of plants, difference of surrounding vegetation, lacks of diverse planting species and structure. We suggest planting the native species of tall tree, shrub and ground cover, edge planting for transitional space between road and natural habitat, planting for foraging and breeding of target animal, diverse layer vegetation, and open space of center for rapid animal dispersal.

Ecological Status and Improvement Suggestion of a Wildlife Road-Crossing Structure at the Jingmaei-Pass in Incheon, Korea (인천시 징매이고개의 도로에 설치한 생태통로의 생태 현황과 개선 방안)

  • Kim, Jinkyoung;Cho, Hyungjin;Cho, Kang-Hyun
    • Ecology and Resilient Infrastructure
    • /
    • v.3 no.3
    • /
    • pp.169-176
    • /
    • 2016
  • Roads are widely accepted to be as a major cause of habitat fragmentation. The wildlife road-crossing structure is one of the most acceptable alternatives among the solutions to provide connectivity between patches isolated by roads. We investigated noise disturbance, vegetation structure and wildlife crossing and habitation at a wildlife road-crossing structure located at the Jingmaei-Pass in Incheon, Korea, to monitor and evaluate its conservation value and ecological performance and to propose measures for their adaptive management. From the result of noise measurement, the noise disturbance from the road traffic was not properly blocked out at the wildlife crossing structure. The survey results of vegetation structure showed that the early-successional plant species such as Ambrosia trifida, Erigeron annuus, Pueraria lobata, Rosa multiflora invaded widely on the crossing structure. An efficient management of the vegetation should be necessarily considered for the facilitation of vegetation succession and the improvement of animal habitat. The crossing structure was used by limited mammal species: Apodemus agrarius, Nyctereutes procyonoides, Mogera wogura and Sciurus vulgaris coreae as the results of the monitoring using footprints and closed-circuit television. In conclusion, The Jingmaei-Pass wildlife crossing structure is unable to function properly as a biological corridor because of the interference of noise and flourishing disturbed vegetation. Therefore, proper alternatives are required for improving animal habitats and mobile environments to enhance the ecological function of a wildlife corridor.

Sex-related demographics in two remnant populations of a dioecious tree Ilex cornuta (Aquifoliaceae): implications for conservation

  • Shin, Sookyung;Lee, Hakbong;Lee, Jei-Wan;Kang, Hyesoon
    • Journal of Ecology and Environment
    • /
    • v.43 no.3
    • /
    • pp.320-331
    • /
    • 2019
  • Background: Dioecious plant species having both male and female plants have been investigated regarding sex-related characteristics such as sex ratio, sex-differential resource requirements, and spatial segregation of the sexes. Habitat loss and fragmentation are major threats to the survival of plant populations, but dioecious species are particularly more prone to such habitat degradation than non-dioecious species because of their dimorphic sexual system. We examined the sex-related demographics of two Ilex cornuta populations being different regarding land use history. Methods: During 2016-2017, we examined I. cornuta trees with a basal diameter ${\geq}1.5cm$ in the Yongsu-ri population (YS population) and the Gotjawal Provincial Park population (GP population). Plant sex (male, female, or unsexed) was identified. The tree size (basal diameter and height of the main stem), clonal production (the ramet numbers per genet), and vitality for each clone were measured. The associations between population, sex, tree size, clonal production, and vitality were examined using ANOVAs and contingency table analyses. Finally, point pattern analyses using O-ring statistics were conducted to assess spatial patterns. Results: Upon excluding unsexed trees, the YS population with 74 trees was significantly male-biased (0.66), while the GP population with only 26 trees had a 1:1 sex ratio. In both populations, males and females did not differ in tree size. Although the mean number of ramets differed significantly between populations, females tended to produce more ramets than males. The proportion of weak trees was significantly higher in the YS than in the GP population. Neither population showed evidence of spatial segregation of the sexes. Conclusions: The two populations of dioecious I. cornuta are characterized by the small number of trees and relatively high frequencies of non-reproductive trees. Both indicate that these populations are quite susceptible to environmental and genetic stochasticity. On the other hand, the differences between populations in sex ratio, clonal production, and vitality suggest that conservation efforts for I. cornuta need to be population-specific. In order to help recover and enable this vulnerable species to persist, it is necessary to find ways to enhance their sexual reproduction and simultaneously reduce habitat disturbances due to anthropogenic activities.

Small-scale spatial genetic structure of Asarum sieboldii metapopulation in a valley

  • Jeong, Hyeon Jin;Kim, Jae Geun
    • Journal of Ecology and Environment
    • /
    • v.45 no.3
    • /
    • pp.97-104
    • /
    • 2021
  • Background: Asarum sieboldii Miq., a species of forest understory vegetation, is an herbaceous perennial belonging to the family Aristolochiaceae. The metapopulation of A. sieboldii is distributed sparsely and has a short seed dispersal distance by ants as their seed distributor. It is known that many flowers of A. sieboldii depend on self-fertilization. Because these characteristics can affect negatively in genetic structure, investigating habitat structure and assessment of genetic structure is needed. A total of 27 individuals in a valley were sampled for measuring genetic diversity, genetic distance, and genetic differentiation by RAPDPCR. Results: The habitat areas of A. sieboldii metapopulation were relatively small (3.78~33.60 m2) and population density was very low (five to seven individuals in 20×20 m quadrat). The habitat of A. sieboldii was a very shady (relative light intensity = 0.9%) and mature forest with a high evenness value (J = 0.81~0.99) and a low dominance value (D = 0.19~0.28). The total genetic diversity of A. sieboldii was quite high (h = 0.338, I = 0.506). A total of 33 band loci were observed in five selected primers, and 31 band loci (94%) were polymorphic. However, genetic differentiation along the valley was highly progressed (Gst = 0.548, Nm = 0.412). The average genetic distance between subpopulations was 0.387. The results of AMOVA showed 52.77% of variance occurs among populations, which is evidence of population structuring. Conclusions: It is expected that a small-scale founder effect had occurred, an individual spread far from the original subpopulation formed a new subpopulation. However, geographical distance between individuals would have been far and genetic flow occurred only within each subpopulation because of the low density of population. This made significant genetic distance between the original and new population by distance. Although genetic diversity of A. sieboldii metapopulation is not as low as concerned, the subpopulation of A. sieboldii can disappear by stochastic events due to small subpopulation size and low density of population. To prevent genetic isolation and to enhance the stable population size, conservative efforts such as increasing the size of each subpopulation or the connection between subpopulations are needed.

Spatial Analysis of Landscape Structure Changes Caused by the US Conservation Reserve Program in the Central High Plains (미중부지역 농지보전 프로그램에 의한 경관구조 변화분석)

  • Park, Sun-Yurp;Egbert, Stephen L
    • Journal of the Korean association of regional geographers
    • /
    • v.9 no.4
    • /
    • pp.519-533
    • /
    • 2003
  • The U.S. Conservation Reserve Program (CRP) resulted in the conversion of approximately 14.8 million ha(36.5 million acres) of cropland to grassland, woodland, and other conservation uses throughout the U.S. between 1986 and 1992. One of the major results of CRP has been the addition of millions of hectares of potential wildlife habitat. primarily as grassland. In this study, we examined regional changes in landscape structure caused by the introduction of CRP. Utilizing multi-seasonal Landsat Thematic Mapper imagery, we produced maps of cropland and grassland for the pre- and post- CRP enrollment periods for a six-county region in southwest Kansas. We then applied post-classification differencing to identify regions of cropland that had been converted to CRP. Using the FRAGSTATS spatial pattern analysis program, we calculated a variety of spatial statistics to analyze changes in landscape structure due to CRP. The major impact of CRP in the six-county study area has been the reversal of an overall trend of grassland habitat fragmentation. From the standpoint of potential wildlife habitat, the introduction of CRP has greatly increased the number of patches, mean patch size, and the interior or core area of grassland patches. In addition, CRP has increased connectivity and aggregation between grassland patches, potentially important factors for species of conservation interest, particularly those that require larger expanses of unbroken habitat. Finally, the distance between neighboring patches of grassland has decreased, reducing travel distance between patches. Clearly, the introduction of CRP has substantially modified the spatial structure of the southwest Kansas landscape, with important implications for wildlife habitat.

  • PDF

Effective Methods on the Conservation of Specific Plant Species

  • Park, In Hwan;Ra, Jung Hwa
    • Journal of Environmental Impact Assessment
    • /
    • v.8 no.1
    • /
    • pp.121-132
    • /
    • 1999
  • 효과적인 특정식물종에 보전대책 수립을 위한 정책척 측면에서의 연구결과를 요약하면 아래와 같다. 1) 특정식물종의 분류항목을 보다 더 세분화하고 세분화된 각 항목별 지정기준을 구체적으로 설정하는 것이 필요하다. 2) 조사의 범위를 특정지역에 대한 부분적 조사가 아니라 국토 및 지역차원에서 총체적으로 이루어져야 하고 조사내용도 특정식물종만이 아닌 타 환경요인들(Biotope, 식물지리적 분포, 토양조건 등)을 함께 조사내용에 포함시킬 필요가 있다. 3) 연구자의 주관적 편견이나 경험에 의한 평가를 지양하고 보다 객관적이고 과학적인 평가체계의 확립이 필요하다. 4) 국가차원에서 특정식물종을 총체적으로 관리할 수 있는 지도제작, 정보시스템의 구축, 현장보전 및 장외보전의 활성화가 필요하다. 본 연구에서 제시된 정책적 차원에서의 개선책은 관계전문가들 사이에 보다 더 구체적인 논의 및 연구를 위한 기초자료 제시로서, 세부적인 연구는 차후 계속 수행되어야 할 것으로 사료된다.

  • PDF

From Fragmented Development to Three-Dimensional and Coordinated Development - Research on Renewal Strategies of Existing Underground Commercial Space in Harbin

  • Xue, Minghui;Su, Yiming;Hu, Jiayu
    • International Journal of High-Rise Buildings
    • /
    • v.10 no.1
    • /
    • pp.17-28
    • /
    • 2021
  • In Harbin, a network of underground commercial spaces has been developed to occupy spaces that were originally created as civil defense shelters. With the gradual extension of the local metro rail system, the existing underground commercial space is no longer an isolated regional development, but a space that represents "three-dimensional city" and coordinated development taking place in many Chinese cities. Based on the analysis of the unique development process taken in underground space of Harbin, this paper summarizes three characteristics of its early model of "fragmented development" of underground space. By conducting a comprehensive field research and survey, the researchers analyzed 472 questionnaires related to the development trend, and proposed multi-level synergistic elements for the renewal and development of underground commercial space. The paper concludes by discussing the trend of "three-dimensional and collaborative development," suitable for the development needs of the new era, and the corresponding development strategies for the renewal of underground space.

Study on Characteristics of Community and Ecology of Fishes in the Newly Constructed Gunwi Dam Reservoir (신규로 건설된 군위댐 호내 어류 군집 및 생태적 특성에 관한 연구)

  • Lee, Jin-Woong;Yoon, Ju-Duk;Kim, Jeong-Hui;Park, Sang-Hyeon;Baek, Seung-Ho;Chang, Kwang-Hyeon;Jang, Min-Ho
    • Korean Journal of Ecology and Environment
    • /
    • v.48 no.4
    • /
    • pp.219-228
    • /
    • 2015
  • To secure water resources, dams are normally constructed on the upper - middle part of streams, and it generates physical disturbances such as habitat alteration and stream fragmentation. Such construction can restrict movement of aquatic organisms, especially for freshwater fish which is one of top predator in aquatic ecosystem, and cause genetic fragmentation and community change. In this study, to investigate impact of habitat alteration after dam construction on freshwater fish, we monitored fish community changes, and compared fish fauna between dam reservoir and inflows. Additionally, movement characteristics and habitat boundaries of four species were identified by radio telemetry method. The study was conducted in the Gunwi Dam which was constructed in December 2010. Radio telemetry was applied to Pungtungia herzi, Zacco platypus (living lotic and lentic), Silurus asotus (lentic preferred species) and Zacco koreanus (lotic preferred species). The number of species was remarkably decreased (4 family, 10 species) comparing with before the dam construction (7 family, 15 species). Specifically, Coreoleuciscus splendidus, Niwaella multifasciata, Liobagrus mediadiposalis, Coreoperca herzi and Odontobutis platycephala that inhabit in the lotic environment were not collected in the study area. A total of 8 species were caught in both the dam reservoir and tributaries except 2 species (C. auratus and S. asotus). Sorenson's similarity between the reservoir and its tributaries was high (0.842). All of the radio tagged species stayed in the reservoir except S. asotus which moved to the tributary. These species mainly utilized the shallow littoral zone as a habitat. These results could be useful as a baseline data for efficient management of fishes in lakes.

Monitoring the Wildlife Use of Culverts and Underpasses Using Snow Tracking in Korea (야생동물의 도로 횡단 특성 분석 -도로횡단구조물 상의 눈 위 발자국 조사를 통하여-)

  • Choi Tae-Young;Lee Yong-Wook;Whang Ki-Young;Kim Seon-Myoung;Park Moon-Sun;Park G-Rim;Cho Beom-Joon;Park Chong-Hwa;Lee Myung-Woo
    • Korean Journal of Environment and Ecology
    • /
    • v.20 no.3
    • /
    • pp.340-344
    • /
    • 2006
  • The objective of this paper was to investigate the potential of road-crossing structures as biological corridors that can overcome wildlife habitat fragmentation caused by road construction. Snow tracking on animal trace adjacent to and under bridges, underpasses, and culverts of eight rural highways in Korea was carried out. A total 89 structures were monitored and the results follow. First, the probability of road crossing increases with the increasing cross sectional size of crossing structures. Second, small to medium sized carnivores such as raccoon dog, leopard cat, and Siberian weasel use all types of structures. Finally, water deer, or large herbivore crossed only under bridges. Consequently, further studies are necessary to identify suitable types of road crossing structures that can mitigate the probability of road-kills and habitat fragmentation of water deer.