• Title/Summary/Keyword: habitat density

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Soil and Environmental Characteristics of Schizandra Chinensis Baillon Habitat Located in Jangsu-gun, Jeollabuk-do (전라북도 장수군 오미자 자생지 토양 및 환경 특성)

  • Lim, Sung-Jin;Lee, Kang-Soo;Jung, Hye-Ran;Kim, Young-Geun;Song, Mi-Sun;Cho, Jae-Young
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.771-775
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    • 2010
  • This study was carried out to investigate soil and environment characteristics of Schizandra Chinensis Baillon habitat as a part of establishment of conservation plan for important medicinal crop resources in Jangsu-gun, Jeollabuk-do. These habitats are mostly located on the slopes of mountains facing northwest at an altitude of 500 m to 700 m with angles of inclination ranging from 17.6 to 36.4%. Average yearly precipitation and temperature of Schizandra Chinensis Baillon habitat were 1,493.4 mm and $16.9^{\circ}C$, respectively. The number of plant species growing in Schizandra Chinensis Baillon habitat was found 55 species. Salix gracilistyla, Lespedeza bicolor, and Artemisia princeps var. were shown higher density and coverage. Chemical quality of Schizandra Chinensis Baillon habitats soils was relatively higher than artificial cultivation soil.

Selection and Management Strategies for Restoration and Conservation Target Sites of Mankyua chejuense using Species Distribution Models (종 분포 모형을 활용한 제주고사리삼의 복원 및 보전 대상지 선정과 관리방안)

  • Lee, Sang-Wook;Jang, Rae-Ik;Oh, Hong-Shik;Jeon, Seong-Woo
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.26 no.3
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    • pp.29-42
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    • 2023
  • As the destruction of habitats due to recent development continues, there is also increasing interest in endangered species. Mankyua chejuense is a vulnerable species that is sensitive to changes in population and habitat, and it has recently been upgraded from Endangered Species II to Endangered Species I, requiring significant management efforts. So in this study, we analyzed the potential habitats of Mankyua chejuense using MaxEnt(Maximum Entropy) modeling. We developed three models: one that considered only environmental characteristics, one that considered artificial factors, and one that reflected the habitat of dominant tree species in the overstory. Based on previous studies, we incorporated environmental and human influence factors for the habitats of Mankyua chejuense into spatial information, and we also used the habitat distribution models of dominant tree species, including Ulmus parvifolia, Maclura tricuspidata, and Ligustrum obtusifolium, that have been previously identified as major overstory species of Mankyua chejuense. Our analysis revealed that rock exposure, elevation, slope, forest type, building density, and soil type were the main factors determining the potential habitat of Mankyua chejuense. Differences among the three models were observed in the edges of the habitats due to human influence factors, and results varied depending on the similarity of the habitats of Mankyua chejuense and the dominant tree species in the overstory. The potential habitats of Mankyua chejuense presented in this study include areas where the species could potentially inhabit in addition to existing habitats. Therefore, these results can be used for the conservation and management planning of Mankyua chejuense.

Mapping the Potential Distribution of Raccoon Dog Habitats: Spatial Statistics and Optimized Deep Learning Approaches

  • Liadira Kusuma Widya;Fatemah Rezaie;Saro Lee
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.4 no.4
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    • pp.159-176
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    • 2023
  • The conservation of the raccoon dog (Nyctereutes procyonoides) in South Korea requires the protection and preservation of natural habitats while additionally ensuring coexistence with human activities. Applying habitat map modeling techniques provides information regarding the distributional patterns of raccoon dogs and assists in the development of future conservation strategies. The purpose of this study is to generate potential habitat distribution maps for the raccoon dog in South Korea using geospatial technology-based models. These models include the frequency ratio (FR) as a bivariate statistical approach, the group method of data handling (GMDH) as a machine learning algorithm, and convolutional neural network (CNN) and long short-term memory (LSTM) as deep learning algorithms. Moreover, the imperialist competitive algorithm (ICA) is used to fine-tune the hyperparameters of the machine learning and deep learning models. Moreover, there are 14 habitat characteristics used for developing the models: elevation, slope, valley depth, topographic wetness index, terrain roughness index, slope height, surface area, slope length and steepness factor (LS factor), normalized difference vegetation index, normalized difference water index, distance to drainage, distance to roads, drainage density, and morphometric features. The accuracy of prediction is evaluated using the area under the receiver operating characteristic curve. The results indicate comparable performances of all models. However, the CNN demonstrates superior capacity for prediction, achieving accuracies of 76.3% and 75.7% for the training and validation processes, respectively. The maps of potential habitat distribution are generated for five different levels of potentiality: very low, low, moderate, high, and very high.

Influence of Forest Fire on Soil Microarthropod Fauna (산불이 토양 미소절지동물상에 미치는 영향)

  • Choi, Seong Sik
    • The Korean Journal of Ecology
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    • v.19 no.3
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    • pp.251-260
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    • 1996
  • The effect of forest fire on soil microarthropod fauna was investigated in the Inhoo Park, located at Deokjin-gu, Chonju city, where fire burned about 2 hectares on April 5, 1994. Vegetation of the area was covered with mixed forest such as 20 to 30 year old black locust, alder, and pine gree, etc., and also rich in understory plants, dead leaves, twigs, etc. The soil samples were taken from burnt soil and near-by control site on April 10, June 6 and Oct. 22 in 1994, and June 26, 1995. Soil microarthropods were extracted using Tullgren apparatus for 72 hours. Soil microarthropods collected in this experiment were 8, 013 at control and 3, 805 at the burnt site making a total of 11, 818 from 5 classes. Therefore, appearance of microarthropods was reduced to 52.5% at burnt site. Dominant animal groups were Acari (45%) and collembola (46%). The reduced rate of soil animal density by fire damage was 52.5% of the total soil microarthropods accounting 36% in Acari and 70% in collembola. The reduction of soil animal density by fire was 65.3% by habitat destruction and 51.7% by diret shock from fire heat. In Collembola, 89% was reduced by habitat destruction. Oribatid mites collected at sample plots included 29 families, 47 genera and 58 species. Forty-two species at burnt site and 47 species at unburnt site were identified, of these 32 being common species at both sites. The density ratio of soil animals at the burnt sites and those at unburnt sites was 38.6% va 61.4% resulting in 37% reduction due to fire. The dominant species with more than 5% in relative density were Trichogalumna nipponica (7.3%) and Eremobelba japonica (5.8%) at unburnt site, shereas 5 species including Eohypochthonius crassisetiger (8.5%) at the burnt site. The number of these species were 32.1% of total number. MGP analysis based on the number of oribatid mites indicated GP type at both unburnt and burnt sites, revealing domination of the P group in oribatid mites.

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Breeding Population and Habitat of Black-tailed Gulls (Larus crassirostris) on Nando Island, Natural Monument (천연기념물 난도에서 번식하는 괭이갈매기 개체군 및 서식 환경)

  • Kim, Miran;Kwon, Young-Soo;Nam, Ki-baek;Lee, Ho;Myeong, Hyeon-Ho;Noh, Hyung Soo
    • Korean Journal of Environmental Biology
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    • v.35 no.2
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    • pp.134-142
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    • 2017
  • Nando Island is reported as one of the biggest breeding colonies of seabirds in South Korea, and is protected as a Natural Monument. This study was conducted between July to November 2015, to investigate the breeding population of Black-tailed gulls and their habitat on Nando Island. We estimated the breeding population of Black-tailed gulls (Larus crassirostris) using nest density. The mean nest density of Black-tailed gulls was $0.51\;per\;1m^2$ ($0.51m^{-2}$), and the breeding population was approximately 26,760 individuals. The dominant vegetation was Echinochloa crusgalli and Agropyron tsukushiense var. transiens, which served as shelter and nest sites to Black-tailed gulls. The diet of Black-tailed gulls was mainly the fish, Japanese Anchovy Engraulis japonicas (48%). Other species which were found to breed on Nando Island were Streaked Sheawater (Calonectris leucomelas), Temminck's Cormorant (Phalacrocorax capillatus), and Swinhoe's storm petrels(Oceanodroma monorhis).

Wildlife Habitat Prediction Model based on Specialist's Experience - A Case Study of Daecheoncheon.Cheongradam - (전문조사원 경험에 의한 야생동물 서식지 예측모형 - 대천천.청라댐 유역을 대상으로 -)

  • Jang, Raeik;Lee, Myoun-Woo
    • Korean Journal of Environment and Ecology
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    • v.28 no.4
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    • pp.393-403
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    • 2014
  • The aim of this study was to use the information deduced from biotopemap in Boryeong, Chungnam province conducted in 2011 and to select the wildlife survey point. The information used for the study was deduced from the knowledge and experience of wildlife specialists and was realized by 6 environmental variables (Outside distance from food vegetation, Outside distance from farm land, Outside distance from forest, Human density, Outside distance from road, Outside distance from water). 6 environmental variables were modeled by map overlay method and the model could deduce the correlation of 94.72% as a result of comparing with occurrence information. The areas predicted to have many occurrences were rural landscapes, forests, and valleys, and they can be used to deduce the quality wildlife survey results in the limit of survey range (area, schedule, and budget). However, it had the limit points such as the inside of forests was excluded, all species did not prefer the same habitat. The following studies are needed for this part in the future.

Differences in Characteristics of Habitat and Rodent Populations Between Before and After Damaged Tree Removals at Forest Fired Areas in Samcheok, Gangwon Province, Korea (강원도 삼척 산불피해지역에서 피해목 제거 전과 후의 서식환경 및 설치류 개체군 특성 차이)

  • Lee, Eun Jae;Lee, Woo-Shin;Lee, Young-Geun;Lee, Myung-Bo;Rhim, Shin-Jae
    • Journal of Korean Society of Forest Science
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    • v.97 no.1
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    • pp.113-117
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    • 2008
  • This study was conducted to clarify the differences in habitat characteristics and rodent populations between before and after damaged tree removals at forest fired areas in coniferous forest, Samcheok, Gangwon Province, Korea. The understory coverage and the number of shrub stem were increased by forest succession. Number of snags and downed CWD (coarse woody debris) were decreased after damaged tree removals. Population density of Apodemus agrarius was increased after damaged tree removal. However, population density of total rodents, Apodemus peninsulae and Eothenomys regulus were decreased. Changes in habitat structures may be influenced in rodent species composition. Especially, that would be negative effect on forestdwelling rodents.

Distribution and habitat use of the endangered Siberian flying squirrel Pteromys volans (Rodentia: Sciuridae)

  • Lim, Sang Jin;Kim, Ki Yoon;Kim, Eui Kyeong;Han, Chang Wook;Park, Yung Chul
    • Journal of Ecology and Environment
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    • v.45 no.4
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    • pp.163-169
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    • 2021
  • Background: Understanding the habitat characteristics of the endangered Siberian flying squirrel Pteromys volans is the first step in conserving and managing the forests it requires for nesting, gliding, and feeding. Therefore, in the present study, we characterized the habitats of P. volans using GIS analysis of 411 forest sites in South Korea where fecal droppings were found. Results: Fecal signs of P. volans were found in various regions in South Korea, including the Baekdudaegan Mountains. GIS analysis with six environmental layers (vegetation type, wood-age class, diameter at breast height [DBH], crown density, elevation, and distance from stream) revealed that fecal signs of P. volans were more frequently found in broad-leaved deciduous forests (42%) located 200-399 m above sea level (43.1%) and 0-199 m from the nearest stream (53%), with 5th class wood-age (35.3%), middle size class DBH (51.1%), and high crown density (71%). Conclusions: The present study provides information on the biotic and abiotic characteristics of P. volans habitats. In South Korea, the fecal droppings of P. volans were found predominantly old deciduous broadleaf forests. Further studies are needed to reveal whether the more frequent occurrence of P. volans dropping in broadleaf forests may be due to a particular preference of this species for the forests or to a simple reflection of the area of the broadleaf forests occupying a much larger area than other forest types in Korea.

Mollusk Species Associated with the Scleractinian Coral Alveopora japonica Eguchi, 1968 Forming a Coral Carpet in Northwestern Jeju Island

  • Ronald G., Noseworthy;Hyun-Ki, Hong;Se-Jong, Ju;Hyun-Sung, Yang;Kwang-Sik, Choi
    • Ocean and Polar Research
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    • v.44 no.4
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    • pp.331-338
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    • 2022
  • The high latitude scleractinian coral Alveopora japonica Eguchi, 1965 occurs in high density in the shallow rocky subtidal in Jeju Island, forming coral carpets. Despite its ecological role providing a unique habitat for other benthic organisms, the benthic fauna associated with the A. japonica coral carpet is poorly known. To identify fauna associated with the coral carpet, we explored three sites dominated by A. japonica and one control site on northwestern Jeju Island in May 2013. Using SCUBA, we collected A. japonica and the epibenthic mega-fauna associated with the colonies in 1×1 m2 and identified them to the species level. At a depth of 10 to 15 m, A. japonica colonies heavily covered the seafloor, forming a layer called a coral carpet, with a density of 94 (Keumneung-ri), 133 (Biyangdo), and 155 (Gwidok-ri) colonies/m2. Thirty-four molluscan species were identified from the four sites, including 20 bivalves and 14 gastropods. The coral carpets were enriched with sessile bivalves compared to the control site, as we identified twenty bivalve and eight gastropod species from the coral carpets. Most bivalve species associated with the coral carpets had tropical-subtropical affinities, while gastropods were mainly subtropical and subtropical-low boreal species. Leiosolenus lischkei M. Huber, 2010, in the family Mytilidae and Barbatia steamsi (Pilsbry, 1895), in the family Arcidae, were the two most abundant bivalve species in the coral carpet, L. lischkei being a borer, and B. stearnsi a nestler. The tropical to subtropical Pacific star shell Astralium haematragum (Menke, 1829)was the most abundant gastropod at the study sites. The bivalves and gastropods associated with the coral carpet were small-sized juveniles or sub-adults, suggesting that the coral carpet provides a micro-habitat for the bivalves and gastropods.

Analysis of Functional Habitat Groups of Benthic Macroinvertebrates according to Changes in the Riverbed (하상 변화에 따른 저서성 대형무척추동물의 서식기능군 분석)

  • Lee, Seul Hee;Lee, Mi Jin;Seo, Eul Won;Lee, Jong Eun
    • Journal of Environmental Science International
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    • v.26 no.3
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    • pp.373-380
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    • 2017
  • This study identified the effect of changes in the riverbed on the benthic macroinvertebrate communities. The benthic macroinvertebrates collected from the surveyed sites belonged to 119 species, 65 families, 20 orders, and 7 classes in 4 phyla. The number of Ephemeroptera, Plecoptera, and Trichoptera (E.P.T) species was 42, 10, and 8, respectively, in the tributary, confluence, and Nakdong River sites. Lotic species (Hydropsychidae) showed a high density at the tributary sites, whereas lentic species (Chironomidae) showed a high density at the confluence and Nakdong River sites. Community analysis showed that the Dominance Index (DI) was 0.54 in tributary sites, and dominance indices increased closer to the Nakdong River sites. The diversity index (H') was inversely proportional to DI. The ratio of Burrowers species (BU) at the surveyed sites increased closer to the Nakdong River sites. Analysis of common species showed 37 species (34.6%) between the tributary and confluence sites and 66 species (51.5%) between the confluence and Nakdong River sites.